18280644 has 24 divisors (see below), whose sum is σ = 45164448. Its totient is φ = 5735040.

The previous prime is 18280631. The next prime is 18280651. The reversal of 18280644 is 44608281.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 44602 + ... + 45009.

It is an arithmetic number, because the mean of its divisors is an integer number (1881852).

Almost surely, 2^18280644 is an apocalyptic number.

It is an amenable number.

18280644 is an abundant number, since it is smaller than the sum of its proper divisors (26883804).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18280644 is a wasteful number, since it uses less digits than its factorization.

18280644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89635 (or 89633 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 33.

The square root of 18280644 is about 4275.5869772465. The cubic root of 18280644 is about 263.4291499136.

The spelling of 18280644 in words is "eighteen million, two hundred eighty thousand, six hundred forty-four".