19656686874 has 64 divisors (see below), whose sum is σ = 43327291392. Its totient is φ = 5895691200.

The previous prime is 19656686837. The next prime is 19656686897. The reversal of 19656686874 is 47868665691.

It is a Harshad number since it is a multiple of its sum of digits (66).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3861559 + ... + 3866645.

It is an arithmetic number, because the mean of its divisors is an integer number (676988928).

Almost surely, 2^19656686874 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19656686874, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21663645696).

19656686874 is an abundant number, since it is smaller than the sum of its proper divisors (23670604518).

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

19656686874 is a wasteful number, since it uses less digits than its factorization.

19656686874 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5691.

The product of its digits is 104509440, while the sum is 66.

The spelling of 19656686874 in words is "nineteen billion, six hundred fifty-six million, six hundred eighty-six thousand, eight hundred seventy-four".