18138884 has 6 divisors (see below), whose sum is σ = 31743054. Its totient is φ = 9069440.

The previous prime is 18138871. The next prime is 18138919. The reversal of 18138884 is 48883181.

It can be written as a sum of positive squares in only one way, i.e., 17825284 + 313600 = 4222^2 + 560^2 .

It is a super-2 number, since 2×18138884² = 658038225530912, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2267357 + ... + 2267364.

It is an arithmetic number, because the mean of its divisors is an integer number (5290509).

Almost surely, 2^18138884 is an apocalyptic number.

It is an amenable number.

18138884 is a deficient number, since it is larger than the sum of its proper divisors (13604170).

18138884 is a wasteful number, since it uses less digits than its factorization.

18138884 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4534725 (or 4534723 counting only the distinct ones).

The product of its digits is 49152, while the sum is 41.

The square root of 18138884 is about 4258.9768724425. The cubic root of 18138884 is about 262.7464485188.

The spelling of 18138884 in words is "eighteen million, one hundred thirty-eight thousand, eight hundred eighty-four".