21115120524 has 12 divisors (see below), whose sum is σ = 49268614584. Its totient is φ = 7038373504.

The previous prime is 21115120517. The next prime is 21115120549. The reversal of 21115120524 is 42502151112.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 21115120494 and 21115120503.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 879796677 + ... + 879796700.

It is an arithmetic number, because the mean of its divisors is an integer number (4105717882).

Almost surely, 2^21115120524 is an apocalyptic number.

It is an amenable number.

21115120524 is an abundant number, since it is smaller than the sum of its proper divisors (28153494060).

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

21115120524 is a wasteful number, since it uses less digits than its factorization.

21115120524 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1759593384 (or 1759593382 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 24.

Adding to 21115120524 its reverse (42502151112), we get a palindrome (63617271636).

The spelling of 21115120524 in words is "twenty-one billion, one hundred fifteen million, one hundred twenty thousand, five hundred twenty-four".