121221120400 has 30 divisors (see below), whose sum is σ = 291233742722. Its totient is φ = 48488448000.

The previous prime is 121221120353. The next prime is 121221120437. The reversal of 121221120400 is 4021122121.

It can be written as a sum of positive squares in 3 ways, for example, as 16875664 + 121204244736 = 4108^2 + 348144^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 151526001 + ... + 151526800.

Almost surely, 2^121221120400 is an apocalyptic number.

121221120400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121221120400 is an abundant number, since it is smaller than the sum of its proper divisors (170012622322).

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

121221120400 is a wasteful number, since it uses less digits than its factorization.

121221120400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 303052819 (or 303052808 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 121221120400 its reverse (4021122121), we get a palindrome (125242242521).

The spelling of 121221120400 in words is "one hundred twenty-one billion, two hundred twenty-one million, one hundred twenty thousand, four hundred".