21427686456 has 32 divisors (see below), whose sum is σ = 58439145600. Its totient is φ = 6493238240.

The previous prime is 21427686439. The next prime is 21427686509. The reversal of 21427686456 is 65468672412.

It is a junction number, because it is equal to n+sod(n) for n = 21427686399 and 21427686408.

It is a congruent number.

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, 40582476 + ... + 40583003.

It is an arithmetic number, because the mean of its divisors is an integer number (1826223300).

Almost surely, 2^21427686456 is an apocalyptic number.

It is an amenable number.

21427686456 is an abundant number, since it is smaller than the sum of its proper divisors (37011459144).

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

21427686456 is a wasteful number, since it uses less digits than its factorization.

21427686456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81165499 (or 81165495 counting only the distinct ones).

The product of its digits is 3870720, while the sum is 51.

The spelling of 21427686456 in words is "twenty-one billion, four hundred twenty-seven million, six hundred eighty-six thousand, four hundred fifty-six".