21044999988 has 48 divisors (see below), whose sum is σ = 54887871360. Its totient is φ = 6972988032.

The previous prime is 21044999957. The next prime is 21044999999. The reversal of 21044999988 is 88999944012.

21044999988 is a `hidden beast` number, since 2 + 10 + 449 + 99 + 98 + 8 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 565381 + ... + 601452.

It is an arithmetic number, because the mean of its divisors is an integer number (1143497320).

Almost surely, 2^21044999988 is an apocalyptic number.

It is an amenable number.

21044999988 is an abundant number, since it is smaller than the sum of its proper divisors (33842871372).

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

21044999988 is a wasteful number, since it uses less digits than its factorization.

21044999988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1167013 (or 1167005 counting only the distinct ones).

The product of its (nonzero) digits is 13436928, while the sum is 63.

The spelling of 21044999988 in words is "twenty-one billion, forty-four million, nine hundred ninety-nine thousand, nine hundred eighty-eight".