21864227872 has 12 divisors (see below), whose sum is σ = 43045198686. Its totient is φ = 10932113920.

The previous prime is 21864227857. The next prime is 21864227911. The reversal of 21864227872 is 27872246812.

It can be written as a sum of positive squares in only one way, i.e., 19677356176 + 2186871696 = 140276^2 + 46764^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 341628529 + ... + 341628592.

Almost surely, 2^21864227872 is an apocalyptic number.

It is an amenable number.

21864227872 is a deficient number, since it is larger than the sum of its proper divisors (21180970814).

21864227872 is an equidigital number, since it uses as much as digits as its factorization.

21864227872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 683257131 (or 683257123 counting only the distinct ones).

The product of its digits is 1204224, while the sum is 49.

The spelling of 21864227872 in words is "twenty-one billion, eight hundred sixty-four million, two hundred twenty-seven thousand, eight hundred seventy-two".