18640655 has 16 divisors (see below), whose sum is σ = 24612768. Its totient is φ = 13552000.

The previous prime is 18640639. The next prime is 18640663. The reversal of 18640655 is 55604681.

It is a happy number.

It is not a de Polignac number, because 18640655 - 2⁴ = 18640639 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5255 + ... + 8055.

It is an arithmetic number, because the mean of its divisors is an integer number (1538298).

Almost surely, 2^18640655 is an apocalyptic number.

18640655 is a deficient number, since it is larger than the sum of its proper divisors (5972113).

18640655 is an equidigital number, since it uses as much as digits as its factorization.

18640655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2839 (or 2817 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 35.

The square root of 18640655 is about 4317.4824840409. The cubic root of 18640655 is about 265.1472066895.

The spelling of 18640655 in words is "eighteen million, six hundred forty thousand, six hundred fifty-five".