18972634 has 4 divisors (see below), whose sum is σ = 28458954. Its totient is φ = 9486316.

The previous prime is 18972623. The next prime is 18972637. The reversal of 18972634 is 43627981.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 43627981 = 97 ⋅449773.

It can be written as a sum of positive squares in only one way, i.e., 18948609 + 24025 = 4353^2 + 155^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (18972637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4743157 + ... + 4743160.

Almost surely, 2^18972634 is an apocalyptic number.

18972634 is a deficient number, since it is larger than the sum of its proper divisors (9486320).

18972634 is an equidigital number, since it uses as much as digits as its factorization.

18972634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9486319.

The product of its digits is 72576, while the sum is 40.

The square root of 18972634 is about 4355.7587169172. The cubic root of 18972634 is about 266.7119919484.

The spelling of 18972634 in words is "eighteen million, nine hundred seventy-two thousand, six hundred thirty-four".