20561677613 has 8 divisors (see below), whose sum is σ = 21234958080. Its totient is φ = 19889022240.

The previous prime is 20561677589. The next prime is 20561677657. The reversal of 20561677613 is 31677616502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20561677613 - 2²⁶ = 20494568749 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20561877613) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 88943 + ... + 221436.

It is an arithmetic number, because the mean of its divisors is an integer number (2654369760).

Almost surely, 2^20561677613 is an apocalyptic number.

It is an amenable number.

20561677613 is a deficient number, since it is larger than the sum of its proper divisors (673280467).

20561677613 is a wasteful number, since it uses less digits than its factorization.

20561677613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 312547.

The product of its (nonzero) digits is 317520, while the sum is 44.

The spelling of 20561677613 in words is "twenty billion, five hundred sixty-one million, six hundred seventy-seven thousand, six hundred thirteen".