21506102613 has 64 divisors (see below), whose sum is σ = 33038668800. Its totient is φ = 13818954240.

The previous prime is 21506102573. The next prime is 21506102617. The reversal of 21506102613 is 31620160512.

21506102613 is a `hidden beast` number, since 2 + 15 + 0 + 610 + 26 + 13 = 666.

It is not a de Polignac number, because 21506102613 - 2⁸ = 21506102357 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21506102617) 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, 31766431 + ... + 31767107.

It is an arithmetic number, because the mean of its divisors is an integer number (516229200).

Almost surely, 2^21506102613 is an apocalyptic number.

It is an amenable number.

21506102613 is a deficient number, since it is larger than the sum of its proper divisors (11532566187).

21506102613 is a wasteful number, since it uses less digits than its factorization.

21506102613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1099 (or 1093 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The spelling of 21506102613 in words is "twenty-one billion, five hundred six million, one hundred two thousand, six hundred thirteen".