21427566455 has 16 divisors (see below), whose sum is σ = 25886770560. Its totient is φ = 17026344192.

The previous prime is 21427566449. The next prime is 21427566463. The reversal of 21427566455 is 55466572412.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21427566455 is a prime.

It is a congruent number.

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, 3952907 + ... + 3958323.

It is an arithmetic number, because the mean of its divisors is an integer number (1617923160).

Almost surely, 2^21427566455 is an apocalyptic number.

21427566455 is a deficient number, since it is larger than the sum of its proper divisors (4459204105).

21427566455 is a wasteful number, since it uses less digits than its factorization.

21427566455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10618.

The product of its digits is 2016000, while the sum is 47.

The spelling of 21427566455 in words is "twenty-one billion, four hundred twenty-seven million, five hundred sixty-six thousand, four hundred fifty-five".