19956625566 has 16 divisors (see below), whose sum is σ = 42013948800. Its totient is φ = 6302092248.

The previous prime is 19956625511. The next prime is 19956625597. The reversal of 19956625566 is 66552665991.

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, 87528946 + ... + 87529173.

It is an arithmetic number, because the mean of its divisors is an integer number (2625871800).

Almost surely, 2^19956625566 is an apocalyptic number.

19956625566 is an abundant number, since it is smaller than the sum of its proper divisors (22057323234).

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

19956625566 is a wasteful number, since it uses less digits than its factorization.

19956625566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175058143.

The product of its digits is 26244000, while the sum is 60.

The spelling of 19956625566 in words is "nineteen billion, nine hundred fifty-six million, six hundred twenty-five thousand, five hundred sixty-six".