19917811716 has 48 divisors (see below), whose sum is σ = 51778621440. Its totient is φ = 5907279520.

The previous prime is 19917811691. The next prime is 19917811733. The reversal of 19917811716 is 61711871991.

It is a happy 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, 1599036 + ... + 1611443.

It is an arithmetic number, because the mean of its divisors is an integer number (1078721280).

Almost surely, 2^19917811716 is an apocalyptic number.

It is an amenable number.

19917811716 is an abundant number, since it is smaller than the sum of its proper divisors (31860809724).

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

19917811716 is a wasteful number, since it uses less digits than its factorization.

19917811716 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3210544 (or 3210542 counting only the distinct ones).

The product of its digits is 190512, while the sum is 51.

The spelling of 19917811716 in words is "nineteen billion, nine hundred seventeen million, eight hundred eleven thousand, seven hundred sixteen".