18400879 has 4 divisors (see below), whose sum is σ = 21029584. Its totient is φ = 15772176.

The previous prime is 18400853. The next prime is 18400883. The reversal of 18400879 is 97800481.

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

It is not a de Polignac number, because 18400879 - 2⁷ = 18400751 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18460879) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1314342 + ... + 1314355.

It is an arithmetic number, because the mean of its divisors is an integer number (5257396).

Almost surely, 2^18400879 is an apocalyptic number.

18400879 is a deficient number, since it is larger than the sum of its proper divisors (2628705).

18400879 is an equidigital number, since it uses as much as digits as its factorization.

18400879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2628704.

The product of its (nonzero) digits is 16128, while the sum is 37.

The square root of 18400879 is about 4289.6245756476. The cubic root of 18400879 is about 264.0054282248.

The spelling of 18400879 in words is "eighteen million, four hundred thousand, eight hundred seventy-nine".