18252778 has 4 divisors (see below), whose sum is σ = 27379170. Its totient is φ = 9126388.

The previous prime is 18252763. The next prime is 18252797. The reversal of 18252778 is 87725281.

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

It can be written as a sum of positive squares in only one way, i.e., 16867449 + 1385329 = 4107^2 + 1177^2 .

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 a self number, because there is not a number n which added to its sum of digits gives 18252778.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4563193 + ... + 4563196.

Almost surely, 2^18252778 is an apocalyptic number.

18252778 is a deficient number, since it is larger than the sum of its proper divisors (9126392).

18252778 is an equidigital number, since it uses as much as digits as its factorization.

18252778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9126391.

The product of its digits is 62720, while the sum is 40.

The square root of 18252778 is about 4272.3270005935. The cubic root of 18252778 is about 263.2952295808.

The spelling of 18252778 in words is "eighteen million, two hundred fifty-two thousand, seven hundred seventy-eight".