19779288172 has 48 divisors (see below), whose sum is σ = 41022392320. Its totient is φ = 8167614912.

The previous prime is 19779288157. The next prime is 19779288187. The reversal of 19779288172 is 27188297791.

It is an interprime number because it is at equal distance from previous prime (19779288157) and next prime (19779288187).

It is a self number, because there is not a number n which added to its sum of digits gives 19779288172.

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, 14029 + ... + 199387.

Almost surely, 2^19779288172 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 19779288172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20511196160).

19779288172 is an abundant number, since it is smaller than the sum of its proper divisors (21243104148).

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

19779288172 is a wasteful number, since it uses less digits than its factorization.

19779288172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185510 (or 185508 counting only the distinct ones).

The product of its digits is 7112448, while the sum is 61.

The spelling of 19779288172 in words is "nineteen billion, seven hundred seventy-nine million, two hundred eighty-eight thousand, one hundred seventy-two".