18261664 has 12 divisors (see below), whose sum is σ = 35952714. Its totient is φ = 9130816.

The previous prime is 18261647. The next prime is 18261667. The reversal of 18261664 is 46616281.

It can be written as a sum of positive squares in only one way, i.e., 11971600 + 6290064 = 3460^2 + 2508^2 .

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (18261667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 285307 + ... + 285370.

Almost surely, 2^18261664 is an apocalyptic number.

It is an amenable number.

18261664 is a deficient number, since it is larger than the sum of its proper divisors (17691050).

18261664 is an equidigital number, since it uses as much as digits as its factorization.

18261664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 570687 (or 570679 counting only the distinct ones).

The product of its digits is 13824, while the sum is 34.

The square root of 18261664 is about 4273.3668225417. The cubic root of 18261664 is about 263.3379493218.

The spelling of 18261664 in words is "eighteen million, two hundred sixty-one thousand, six hundred sixty-four".