21208297872 has 80 divisors (see below), whose sum is σ = 55103973120. Its totient is φ = 7028775936.

The previous prime is 21208297867. The next prime is 21208297889. The reversal of 21208297872 is 27879280212.

It is a Harshad number since it is a multiple of its sum of digits (48).

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, 10748278 + ... + 10750250.

It is an arithmetic number, because the mean of its divisors is an integer number (688799664).

Almost surely, 2^21208297872 is an apocalyptic number.

It is an amenable number.

21208297872 is an abundant number, since it is smaller than the sum of its proper divisors (33895675248).

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

21208297872 is a wasteful number, since it uses less digits than its factorization.

21208297872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3160 (or 3154 counting only the distinct ones).

The product of its (nonzero) digits is 451584, while the sum is 48.

The spelling of 21208297872 in words is "twenty-one billion, two hundred eight million, two hundred ninety-seven thousand, eight hundred seventy-two".