121555600 has 30 divisors (see below), whose sum is σ = 292038290. Its totient is φ = 48622080.

The previous prime is 121555591. The next prime is 121555607. The reversal of 121555600 is 6555121.

It can be written as a sum of positive squares in 3 ways, for example, as 10969344 + 110586256 = 3312^2 + 10516^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is not an unprimeable number, because it can be changed into a prime (121555607) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 151545 + ... + 152344.

Almost surely, 2^121555600 is an apocalyptic number.

121555600 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121555600 is an abundant number, since it is smaller than the sum of its proper divisors (170482690).

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

121555600 is a wasteful number, since it uses less digits than its factorization.

121555600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 303907 (or 303896 counting only the distinct ones).

The product of its (nonzero) digits is 1500, while the sum is 25.

The square root of 121555600 is about 11025.2256212742. The cubic root of 121555600 is about 495.3646260824.

The spelling of 121555600 in words is "one hundred twenty-one million, five hundred fifty-five thousand, six hundred".