18918274 has 4 divisors (see below), whose sum is σ = 28377414. Its totient is φ = 9459136.

The previous prime is 18918253. The next prime is 18918307. The reversal of 18918274 is 47281981.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 47281981 = 17 ⋅2781293.

It can be written as a sum of positive squares in only one way, i.e., 15880225 + 3038049 = 3985^2 + 1743^2 .

It is a super-2 number, since 2×18918274² = 715802182278152, which contains 22 as substring.

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 an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4729567 + ... + 4729570.

Almost surely, 2^18918274 is an apocalyptic number.

18918274 is a deficient number, since it is larger than the sum of its proper divisors (9459140).

18918274 is an equidigital number, since it uses as much as digits as its factorization.

18918274 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9459139.

The product of its digits is 32256, while the sum is 40.

The square root of 18918274 is about 4349.5142257498. The cubic root of 18918274 is about 266.4570223807.

The spelling of 18918274 in words is "eighteen million, nine hundred eighteen thousand, two hundred seventy-four".