19161581568 has 384 divisors, whose sum is σ = 56302646400. Its totient is φ = 5780275200.

The previous prime is 19161581519. The next prime is 19161581657. The reversal of 19161581568 is 86518516191.

It is a tau number, because it is divible by the number of its divisors (384).

It is a self number, because there is not a number n which added to its sum of digits gives 19161581568.

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, 314124258 + ... + 314124318.

It is an arithmetic number, because the mean of its divisors is an integer number (146621475).

Almost surely, 2^19161581568 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 19161581568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28151323200).

19161581568 is an abundant number, since it is smaller than the sum of its proper divisors (37141064832).

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

19161581568 is a wasteful number, since it uses less digits than its factorization.

19161581568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199 (or 179 counting only the distinct ones).

The product of its digits is 518400, while the sum is 51.

The spelling of 19161581568 in words is "nineteen billion, one hundred sixty-one million, five hundred eighty-one thousand, five hundred sixty-eight".