20051561012 has 24 divisors (see below), whose sum is σ = 40610760960. Its totient is φ = 8484746400.

The previous prime is 20051561009. The next prime is 20051561027. The reversal of 20051561012 is 21016515002.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4530239 + ... + 4534662.

It is an arithmetic number, because the mean of its divisors is an integer number (1692115040).

Almost surely, 2^20051561012 is an apocalyptic number.

It is an amenable number.

20051561012 is an abundant number, since it is smaller than the sum of its proper divisors (20559199948).

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

20051561012 is a wasteful number, since it uses less digits than its factorization.

20051561012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9064991 (or 9064989 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 23.

The spelling of 20051561012 in words is "twenty billion, fifty-one million, five hundred sixty-one thousand, twelve".