18913039891 has 8 divisors (see below), whose sum is σ = 19977165824. Its totient is φ = 17877290760.

The previous prime is 18913039883. The next prime is 18913039919. The reversal of 18913039891 is 19893031981.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18913039891 - 2³ = 18913039883 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18913039091) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7092831 + ... + 7095496.

It is an arithmetic number, because the mean of its divisors is an integer number (2497145728).

Almost surely, 2^18913039891 is an apocalyptic number.

18913039891 is a deficient number, since it is larger than the sum of its proper divisors (1064125933).

18913039891 is a wasteful number, since it uses less digits than its factorization.

18913039891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14188401.

The product of its (nonzero) digits is 419904, while the sum is 52.

The spelling of 18913039891 in words is "eighteen billion, nine hundred thirteen million, thirty-nine thousand, eight hundred ninety-one".