121512215120 has 80 divisors (see below), whose sum is σ = 299225022480. Its totient is φ = 45731930112.

The previous prime is 121512215119. The next prime is 121512215129. The reversal of 121512215120 is 21512215121.

It can be written as a sum of positive squares in 8 ways, for example, as 22448429584 + 99063785536 = 149828^2 + 314744^2 .

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

It is a super-2 number, since 2×121512215120² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121512215129) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5228486 + ... + 5251674.

It is an arithmetic number, because the mean of its divisors is an integer number (3740312781).

Almost surely, 2^121512215120 is an apocalyptic number.

121512215120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121512215120 is an abundant number, since it is smaller than the sum of its proper divisors (177712807360).

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

121512215120 is a wasteful number, since it uses less digits than its factorization.

121512215120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27072 (or 27066 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 23.

Subtracting from 121512215120 its reverse (21512215121), we obtain a palindrome (99999999999).

The spelling of 121512215120 in words is "one hundred twenty-one billion, five hundred twelve million, two hundred fifteen thousand, one hundred twenty".