18641643 has 8 divisors (see below), whose sum is σ = 24878400. Its totient is φ = 12416328.

The previous prime is 18641629. The next prime is 18641653. The reversal of 18641643 is 34614681.

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

It is not a de Polignac number, because 18641643 - 2⁴ = 18641627 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18641653) 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, 2248 + ... + 6506.

It is an arithmetic number, because the mean of its divisors is an integer number (3109800).

Almost surely, 2^18641643 is an apocalyptic number.

18641643 is a deficient number, since it is larger than the sum of its proper divisors (6236757).

18641643 is a wasteful number, since it uses less digits than its factorization.

18641643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5721.

The product of its digits is 13824, while the sum is 33.

The square root of 18641643 is about 4317.5969010550. The cubic root of 18641643 is about 265.1518910888.

The spelling of 18641643 in words is "eighteen million, six hundred forty-one thousand, six hundred forty-three".