18920931 has 8 divisors (see below), whose sum is σ = 25764864. Its totient is φ = 12345480.

The previous prime is 18920921. The next prime is 18920939. The reversal of 18920931 is 13902981.

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

It is not a de Polignac number, because 18920931 - 2⁵ = 18920899 is a prime.

It is a super-2 number, since 2×18920931² = 716003259813522, which contains 22 as substring.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 18920892 and 18920901.

It is not an unprimeable number, because it can be changed into a prime (18920939) 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, 66955 + ... + 67236.

It is an arithmetic number, because the mean of its divisors is an integer number (3220608).

Almost surely, 2^18920931 is an apocalyptic number.

18920931 is a deficient number, since it is larger than the sum of its proper divisors (6843933).

18920931 is a wasteful number, since it uses less digits than its factorization.

18920931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134241.

The product of its (nonzero) digits is 3888, while the sum is 33.

The square root of 18920931 is about 4349.8196514338. The cubic root of 18920931 is about 266.4694960903.

The spelling of 18920931 in words is "eighteen million, nine hundred twenty thousand, nine hundred thirty-one".