18555640365 has 16 divisors (see below), whose sum is σ = 29717352000. Its totient is φ = 9886899072.

The previous prime is 18555640357. The next prime is 18555640381. The reversal of 18555640365 is 56304655581.

It is a happy number.

It is not a de Polignac number, because 18555640365 - 2³ = 18555640357 is a prime.

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, 573895 + ... + 605364.

It is an arithmetic number, because the mean of its divisors is an integer number (1857334500).

Almost surely, 2^18555640365 is an apocalyptic number.

18555640365 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18555640365 is a deficient number, since it is larger than the sum of its proper divisors (11161711635).

18555640365 is a wasteful number, since it uses less digits than its factorization.

18555640365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1180316.

The product of its (nonzero) digits is 2160000, while the sum is 48.

The spelling of 18555640365 in words is "eighteen billion, five hundred fifty-five million, six hundred forty thousand, three hundred sixty-five".