121520400 has 60 divisors (see below), whose sum is σ = 389274192. Its totient is φ = 32405120.

The previous prime is 121520393. The next prime is 121520419. The reversal of 121520400 is 4025121.

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 121520400.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 49434 + ... + 51833.

Almost surely, 2^121520400 is an apocalyptic number.

121520400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121520400 is an abundant number, since it is smaller than the sum of its proper divisors (267753792).

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

121520400 is a wasteful number, since it uses less digits than its factorization.

121520400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101288 (or 101277 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 121520400 is about 11023.6291664769. The cubic root of 121520400 is about 495.3168056660.

Adding to 121520400 its reverse (4025121), we get a palindrome (125545521).

The spelling of 121520400 in words is "one hundred twenty-one million, five hundred twenty thousand, four hundred".