21044408136 has 32 divisors (see below), whose sum is σ = 53202160800. Its totient is φ = 6935984000.

The previous prime is 21044408131. The next prime is 21044408149. The reversal of 21044408136 is 63180444012.

It is a super-2 number, since 2×21044408136² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21044408097 and 21044408106.

It is not an unprimeable number, because it can be changed into a prime (21044408131) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4923990 + ... + 4928261.

It is an arithmetic number, because the mean of its divisors is an integer number (1662567525).

Almost surely, 2^21044408136 is an apocalyptic number.

It is an amenable number.

21044408136 is an abundant number, since it is smaller than the sum of its proper divisors (32157752664).

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

21044408136 is a wasteful number, since it uses less digits than its factorization.

21044408136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9852349 (or 9852345 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 33.

The spelling of 21044408136 in words is "twenty-one billion, forty-four million, four hundred eight thousand, one hundred thirty-six".