18665990291 has 4 divisors (see below), whose sum is σ = 20101835712. Its totient is φ = 17230144872.

The previous prime is 18665990243. The next prime is 18665990297. The reversal of 18665990291 is 19209956681.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18665990291 - 2¹⁰ = 18665989267 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18665990297) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 717922691 + ... + 717922716.

It is an arithmetic number, because the mean of its divisors is an integer number (5025458928).

Almost surely, 2^18665990291 is an apocalyptic number.

18665990291 is a deficient number, since it is larger than the sum of its proper divisors (1435845421).

18665990291 is a wasteful number, since it uses less digits than its factorization.

18665990291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1435845420.

The product of its (nonzero) digits is 2099520, while the sum is 56.

The spelling of 18665990291 in words is "eighteen billion, six hundred sixty-five million, nine hundred ninety thousand, two hundred ninety-one".