18331776 has 48 divisors (see below), whose sum is σ = 52754910. Its totient is φ = 6110208.

The previous prime is 18331769. The next prime is 18331777. The reversal of 18331776 is 67713381.

It can be written as a sum of positive squares in only one way, i.e., 13133376 + 5198400 = 3624^2 + 2280^2 .

It is a tau number, because it is divible by the number of its divisors (48).

It is a super-2 number, since 2×18331776² = 672108022628352, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 18331776.

It is not an unprimeable number, because it can be changed into a prime (18331777) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6805 + ... + 9108.

Almost surely, 2^18331776 is an apocalyptic number.

18331776 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

18331776 is an abundant number, since it is smaller than the sum of its proper divisors (34423134).

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

18331776 is a wasteful number, since it uses less digits than its factorization.

18331776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15933 (or 15918 counting only the distinct ones).

The product of its digits is 21168, while the sum is 36.

The square root of 18331776 is about 4281.5623316729. The cubic root of 18331776 is about 263.6745300417.

The spelling of 18331776 in words is "eighteen million, three hundred thirty-one thousand, seven hundred seventy-six".