18087644 has 12 divisors (see below), whose sum is σ = 31756704. Its totient is φ = 9014304.

The previous prime is 18087613. The next prime is 18087647. The reversal of 18087644 is 44678081.

It is a junction number, because it is equal to n+sod(n) for n = 18087598 and 18087607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18087647) 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, 5972 + ... + 8475.

It is an arithmetic number, because the mean of its divisors is an integer number (2646392).

Almost surely, 2^18087644 is an apocalyptic number.

It is an amenable number.

18087644 is a deficient number, since it is larger than the sum of its proper divisors (13669060).

18087644 is a wasteful number, since it uses less digits than its factorization.

18087644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14764 (or 14762 counting only the distinct ones).

The product of its (nonzero) digits is 43008, while the sum is 38.

The square root of 18087644 is about 4252.9570888971. The cubic root of 18087644 is about 262.4988069485.

The spelling of 18087644 in words is "eighteen million, eighty-seven thousand, six hundred forty-four".