21388668872 has 32 divisors (see below), whose sum is σ = 41598590880. Its totient is φ = 10302526080.

The previous prime is 21388668869. The next prime is 21388668901. The reversal of 21388668872 is 27886688312.

It is a super-2 number, since 2×21388668872² (a number of 21 digits) contains 22 as substring.

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, 400754 + ... + 450977.

It is an arithmetic number, because the mean of its divisors is an integer number (1299955965).

Almost surely, 2^21388668872 is an apocalyptic number.

It is an amenable number.

21388668872 is a deficient number, since it is larger than the sum of its proper divisors (20209922008).

21388668872 is a wasteful number, since it uses less digits than its factorization.

21388668872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 851853 (or 851849 counting only the distinct ones).

The product of its digits is 12386304, while the sum is 59.

The spelling of 21388668872 in words is "twenty-one billion, three hundred eighty-eight million, six hundred sixty-eight thousand, eight hundred seventy-two".