21115360501564 has 48 divisors (see below), whose sum is σ = 42895384551936. Its totient is φ = 8907428174400.

The previous prime is 21115360501549. The next prime is 21115360501601. The reversal of 21115360501564 is 46510506351112.

It is a super-2 number, since 2×21115360501564² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7444822 + ... + 9882109.

It is an arithmetic number, because the mean of its divisors is an integer number (893653844832).

Almost surely, 2^{21115360501564} is an apocalyptic number.

It is an amenable number.

21115360501564 is an abundant number, since it is smaller than the sum of its proper divisors (21780024050372).

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

21115360501564 is a wasteful number, since it uses less digits than its factorization.

21115360501564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17327626 (or 17327624 counting only the distinct ones).

The product of its (nonzero) digits is 108000, while the sum is 40.

Adding to 21115360501564 its reverse (46510506351112), we get a palindrome (67625866852676).

The spelling of 21115360501564 in words is "twenty-one trillion, one hundred fifteen billion, three hundred sixty million, five hundred one thousand, five hundred sixty-four".