181664656 has 10 divisors (see below), whose sum is σ = 351975302. Its totient is φ = 90832320.

The previous prime is 181664653. The next prime is 181664657. The reversal of 181664656 is 656466181.

It can be written as a sum of positive squares in only one way, i.e., 175827600 + 5837056 = 13260^2 + 2416^2 .

It is not an unprimeable number, because it can be changed into a prime (181664653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5677005 + ... + 5677036.

Almost surely, 2^181664656 is an apocalyptic number.

181664656 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

181664656 is a deficient number, since it is larger than the sum of its proper divisors (170310646).

181664656 is a wasteful number, since it uses less digits than its factorization.

181664656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11354049 (or 11354043 counting only the distinct ones).

The product of its digits is 207360, while the sum is 43.

The square root of 181664656 is about 13478.3031572969. The cubic root of 181664656 is about 566.3568360874.

It can be divided in two parts, 18166 and 4656, that added together give a palindrome (22822).

The spelling of 181664656 in words is "one hundred eighty-one million, six hundred sixty-four thousand, six hundred fifty-six".