18719896643 has 12 divisors (see below), whose sum is σ = 22051859040. Its totient is φ = 15842513232.

The previous prime is 18719896621. The next prime is 18719896667. The reversal of 18719896643 is 34669891781.

It is not a de Polignac number, because 18719896643 - 2³² = 14424929347 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18719896603) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2414096 + ... + 2421837.

It is an arithmetic number, because the mean of its divisors is an integer number (1837654920).

Almost surely, 2^18719896643 is an apocalyptic number.

18719896643 is a deficient number, since it is larger than the sum of its proper divisors (3331962397).

18719896643 is an equidigital number, since it uses as much as digits as its factorization.

18719896643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4836026 (or 4836019 counting only the distinct ones).

The product of its digits is 15676416, while the sum is 62.

The spelling of 18719896643 in words is "eighteen billion, seven hundred nineteen million, eight hundred ninety-six thousand, six hundred forty-three".