18023857 has 4 divisors (see below), whose sum is σ = 18155556. Its totient is φ = 17892160.

The previous prime is 18023849. The next prime is 18023909. The reversal of 18023857 is 75832081.

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

It can be written as a sum of positive squares in 2 ways, for example, as 11048976 + 6974881 = 3324^2 + 2641^2 .

It is a cyclic number.

It is not a de Polignac number, because 18023857 - 2³ = 18023849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18123857) 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, 65644 + ... + 65917.

It is an arithmetic number, because the mean of its divisors is an integer number (4538889).

Almost surely, 2^18023857 is an apocalyptic number.

It is an amenable number.

18023857 is a deficient number, since it is larger than the sum of its proper divisors (131699).

18023857 is a wasteful number, since it uses less digits than its factorization.

18023857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131698.

The product of its (nonzero) digits is 13440, while the sum is 34.

The square root of 18023857 is about 4245.4513305419. The cubic root of 18023857 is about 262.1898716900.

The spelling of 18023857 in words is "eighteen million, twenty-three thousand, eight hundred fifty-seven".