21612640773455 has 32 divisors (see below), whose sum is σ = 26131951693824. Its totient is φ = 17159203990656.

The previous prime is 21612640773443. The next prime is 21612640773509. The reversal of 21612640773455 is 55437704621612.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21612640773455 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21612640773397 and 21612640773406.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3910371902 + ... + 3910377428.

It is an arithmetic number, because the mean of its divisors is an integer number (816623490432).

Almost surely, 2^{21612640773455} is an apocalyptic number.

21612640773455 is a deficient number, since it is larger than the sum of its proper divisors (4519310920369).

21612640773455 is a wasteful number, since it uses less digits than its factorization.

21612640773455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10815.

The product of its (nonzero) digits is 8467200, while the sum is 53.

The spelling of 21612640773455 in words is "twenty-one trillion, six hundred twelve billion, six hundred forty million, seven hundred seventy-three thousand, four hundred fifty-five".