181764942921 has 45 divisors (see below), whose sum is σ = 274415932791. Its totient is φ = 119900169648.

The previous prime is 181764942913. The next prime is 181764942923. The reversal of 181764942921 is 129249467181.

The square root of 181764942921 is 426339.

It is a perfect power (a square), and thus also a powerful number.

181764942921 is a `hidden beast` number, since 1 + 8 + 176 + 49 + 429 + 2 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 98800205625 + 82964737296 = 314325^2 + 288036^2 .

It is not a de Polignac number, because 181764942921 - 2³ = 181764942913 is a prime.

It is not an unprimeable number, because it can be changed into a prime (181764942923) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 487305291 + ... + 487305663.

Almost surely, 2^181764942921 is an apocalyptic number.

181764942921 is the 426339-th square number.

181764942921 is the 213170-th centered octagonal number.

It is an amenable number.

181764942921 is a deficient number, since it is larger than the sum of its proper divisors (92650989870).

181764942921 is an frugal number, since it uses more digits than its factorization.

181764942921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1012 (or 503 counting only the distinct ones).

The product of its digits is 1741824, while the sum is 54.

The spelling of 181764942921 in words is "one hundred eighty-one billion, seven hundred sixty-four million, nine hundred forty-two thousand, nine hundred twenty-one".