121440400 has 135 divisors (see below), whose sum is σ = 318908811. Its totient is φ = 44432640.

The previous prime is 121440377. The next prime is 121440409. The reversal of 121440400 is 4044121.

The square root of 121440400 is 11020.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 1669264 + 119771136 = 1292^2 + 10944^2 .

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121440409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 4187586 + ... + 4187614.

Almost surely, 2^121440400 is an apocalyptic number.

121440400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

121440400 is the 11020-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 121440400

121440400 is an abundant number, since it is smaller than the sum of its proper divisors (197468411).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

121440400 is a wasteful number, since it uses less digits than its factorization.

121440400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114 (or 55 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

The cubic root of 121440400 is about 495.2080885477.

Multiplying 121440400 by its sum of digits (16), we get a square (1943046400 = 44080²).

121440400 divided by its sum of digits (16) gives a square (7590025 = 2755²).

Adding to 121440400 its reverse (4044121), we get a palindrome (125484521).

Multiplying 121440400 by its reverse (4044121), we get a square (491119671888400 = 22161220²).

It can be divided in two parts, 1214 and 40400, that added together give a palindrome (41614).

The spelling of 121440400 in words is "one hundred twenty-one million, four hundred forty thousand, four hundred".