18376561 has 4 divisors (see below), whose sum is σ = 21001792. Its totient is φ = 15751332.

The previous prime is 18376511. The next prime is 18376597. The reversal of 18376561 is 16567381.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18376561 - 2⁹ = 18376049 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18376561.

It is not an unprimeable number, because it can be changed into a prime (18376511) 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, 1312605 + ... + 1312618.

It is an arithmetic number, because the mean of its divisors is an integer number (5250448).

Almost surely, 2^18376561 is an apocalyptic number.

It is an amenable number.

18376561 is a deficient number, since it is larger than the sum of its proper divisors (2625231).

18376561 is an equidigital number, since it uses as much as digits as its factorization.

18376561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2625230.

The product of its digits is 30240, while the sum is 37.

The square root of 18376561 is about 4286.7891247413. The cubic root of 18376561 is about 263.8890766405.

The spelling of 18376561 in words is "eighteen million, three hundred seventy-six thousand, five hundred sixty-one".