121223440 has 80 divisors (see below), whose sum is σ = 305449200. Its totient is φ = 44476416.

The previous prime is 121223419. The next prime is 121223461. The reversal of 121223440 is 44322121.

It is an interprime number because it is at equal distance from previous prime (121223419) and next prime (121223461).

It can be written as a sum of positive squares in 8 ways, for example, as 3196944 + 118026496 = 1788^2 + 10864^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 237906 + ... + 238414.

It is an arithmetic number, because the mean of its divisors is an integer number (3818115).

Almost surely, 2^121223440 is an apocalyptic number.

121223440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 121223440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (152724600).

121223440 is an abundant number, since it is smaller than the sum of its proper divisors (184225760).

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

121223440 is a wasteful number, since it uses less digits than its factorization.

121223440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 764 (or 758 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 121223440 is about 11010.1516792458. The cubic root of 121223440 is about 494.9130071932.

Adding to 121223440 its reverse (44322121), we get a palindrome (165545561).

The spelling of 121223440 in words is "one hundred twenty-one million, two hundred twenty-three thousand, four hundred forty".