20931722613 has 12 divisors (see below), whose sum is σ = 30235983648. Its totient is φ = 13953894120.

The previous prime is 20931722599. The next prime is 20931722627. The reversal of 20931722613 is 31622713902.

20931722613 is a `hidden beast` number, since 2 + 0 + 9 + 3 + 17 + 22 + 613 = 666.

It is an interprime number because it is at equal distance from previous prime (20931722599) and next prime (20931722627).

It is not a de Polignac number, because 20931722613 - 2⁴ = 20931722597 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20931722633) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 335506 + ... + 392972.

It is an arithmetic number, because the mean of its divisors is an integer number (2519665304).

Almost surely, 2^20931722613 is an apocalyptic number.

It is an amenable number.

20931722613 is a deficient number, since it is larger than the sum of its proper divisors (9304261035).

20931722613 is a wasteful number, since it uses less digits than its factorization.

20931722613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97944 (or 97941 counting only the distinct ones).

The product of its (nonzero) digits is 27216, while the sum is 36.

The spelling of 20931722613 in words is "twenty billion, nine hundred thirty-one million, seven hundred twenty-two thousand, six hundred thirteen".