19561856088 has 64 divisors (see below), whose sum is σ = 49972930560. Its totient is φ = 6378334976.

The previous prime is 19561856077. The next prime is 19561856113. The reversal of 19561856088 is 88065816591.

It is a happy number.

It is a Smith number, since the sum of its digits (57) coincides with the sum of the digits of its prime factors.

It is a congruent number.

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, 2695681 + ... + 2702927.

It is an arithmetic number, because the mean of its divisors is an integer number (780827040).

Almost surely, 2^19561856088 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 19561856088, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24986465280).

19561856088 is an abundant number, since it is smaller than the sum of its proper divisors (30411074472).

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

19561856088 is a wasteful number, since it uses less digits than its factorization.

19561856088 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9696 (or 9692 counting only the distinct ones).

The product of its (nonzero) digits is 4147200, while the sum is 57.

The spelling of 19561856088 in words is "nineteen billion, five hundred sixty-one million, eight hundred fifty-six thousand, eighty-eight".