20561677612 has 48 divisors (see below), whose sum is σ = 42244554240. Its totient is φ = 8573097600.

The previous prime is 20561677589. The next prime is 20561677657. The reversal of 20561677612 is 21677616502.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 387187 + ... + 437077.

It is an arithmetic number, because the mean of its divisors is an integer number (880094880).

Almost surely, 2^20561677612 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20561677612, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21122277120).

20561677612 is an abundant number, since it is smaller than the sum of its proper divisors (21682876628).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20561677612 is a wasteful number, since it uses less digits than its factorization.

20561677612 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50302 (or 50300 counting only the distinct ones).

The product of its (nonzero) digits is 211680, while the sum is 43.

The spelling of 20561677612 in words is "twenty billion, five hundred sixty-one million, six hundred seventy-seven thousand, six hundred twelve".