18520078 has 4 divisors (see below), whose sum is σ = 27780120. Its totient is φ = 9260038.

The previous prime is 18520063. The next prime is 18520097. The reversal of 18520078 is 87002581.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87002581 = 29 ⋅3000089.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4630018 + ... + 4630021.

It is an arithmetic number, because the mean of its divisors is an integer number (6945030).

Almost surely, 2^18520078 is an apocalyptic number.

18520078 is a deficient number, since it is larger than the sum of its proper divisors (9260042).

18520078 is an equidigital number, since it uses as much as digits as its factorization.

18520078 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9260041.

The product of its (nonzero) digits is 4480, while the sum is 31.

The square root of 18520078 is about 4303.4960206790. The cubic root of 18520078 is about 264.5742683539.

The spelling of 18520078 in words is "eighteen million, five hundred twenty thousand, seventy-eight".