21655364056443 has 64 divisors (see below), whose sum is σ = 36152934952960. Its totient is φ = 12719829945600.

The previous prime is 21655364056369. The next prime is 21655364056457. The reversal of 21655364056443 is 34465046355612.

21655364056443 is a `hidden beast` number, since 2 + 1 + 6 + 5 + 5 + 36 + 4 + 0 + 564 + 43 = 666.

It is not a de Polignac number, because 21655364056443 - 2⁸ = 21655364056187 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21655364056443.

It is not an unprimeable number, because it can be changed into a prime (21655364056243) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 12837193 + ... + 14425818.

It is an arithmetic number, because the mean of its divisors is an integer number (564889608640).

Almost surely, 2^{21655364056443} is an apocalyptic number.

21655364056443 is a deficient number, since it is larger than the sum of its proper divisors (14497570896517).

21655364056443 is a wasteful number, since it uses less digits than its factorization.

21655364056443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27263137 (or 27263131 counting only the distinct ones).

The product of its (nonzero) digits is 31104000, while the sum is 54.

The spelling of 21655364056443 in words is "twenty-one trillion, six hundred fifty-five billion, three hundred sixty-four million, fifty-six thousand, four hundred forty-three".