121840400 has 60 divisors (see below), whose sum is σ = 319344144. Its totient is φ = 44304000.

The previous prime is 121840399. The next prime is 121840409. The reversal of 121840400 is 4048121.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (121840409) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9446 + ... + 18245.

Almost surely, 2^121840400 is an apocalyptic number.

121840400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121840400 is an abundant number, since it is smaller than the sum of its proper divisors (197503744).

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

121840400 is a wasteful number, since it uses less digits than its factorization.

121840400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27720 (or 27709 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 20.

The square root of 121840400 is about 11038.1339002569. The cubic root of 121840400 is about 495.7511976244.

Adding to 121840400 its reverse (4048121), we get a palindrome (125888521).

The spelling of 121840400 in words is "one hundred twenty-one million, eight hundred forty thousand, four hundred".