18400079 has 4 divisors (see below), whose sum is σ = 18582360. Its totient is φ = 18217800.

The previous prime is 18400073. The next prime is 18400091. The reversal of 18400079 is 97000481.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18400079 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 (18400073) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 90989 + ... + 91190.

It is an arithmetic number, because the mean of its divisors is an integer number (4645590).

Almost surely, 2^18400079 is an apocalyptic number.

18400079 is a deficient number, since it is larger than the sum of its proper divisors (182281).

18400079 is a wasteful number, since it uses less digits than its factorization.

18400079 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 182280.

The product of its (nonzero) digits is 2016, while the sum is 29.

The square root of 18400079 is about 4289.5313263805. The cubic root of 18400079 is about 264.0016021865.

The spelling of 18400079 in words is "eighteen million, four hundred thousand, seventy-nine".