21011101504 has 56 divisors (see below), whose sum is σ = 42116527400. Its totient is φ = 10399574016.

The previous prime is 21011101487. The next prime is 21011101589. The reversal of 21011101504 is 40510111012.

It can be written as a sum of positive squares in 4 ways, for example, as 1734555904 + 19276545600 = 41648^2 + 138840^2 .

It is a super-2 number, since 2×21011101504² (a number of 21 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2779522 + ... + 2787070.

Almost surely, 2^21011101504 is an apocalyptic number.

It is an amenable number.

21011101504 is an abundant number, since it is smaller than the sum of its proper divisors (21105425896).

21011101504 is a wasteful number, since it uses less digits than its factorization.

21011101504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7995 (or 7985 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 16.

Adding to 21011101504 its reverse (40510111012), we get a palindrome (61521212516).

The spelling of 21011101504 in words is "twenty-one billion, eleven million, one hundred one thousand, five hundred four".