18478664 has 16 divisors (see below), whose sum is σ = 34955820. Its totient is φ = 9157120.

The previous prime is 18478619. The next prime is 18478679. The reversal of 18478664 is 46687481.

It can be written as a sum of positive squares in 2 ways, for example, as 18130564 + 348100 = 4258^2 + 590^2 .

It is a super-2 number, since 2×18478664² = 682922046449792, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9317 + ... + 11124.

Almost surely, 2^18478664 is an apocalyptic number.

It is an amenable number.

18478664 is a deficient number, since it is larger than the sum of its proper divisors (16477156).

18478664 is a wasteful number, since it uses less digits than its factorization.

18478664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20560 (or 20556 counting only the distinct ones).

The product of its digits is 258048, while the sum is 44.

The square root of 18478664 is about 4298.6816583692. The cubic root of 18478664 is about 264.3769103622.

The spelling of 18478664 in words is "eighteen million, four hundred seventy-eight thousand, six hundred sixty-four".