189174721 has 6 divisors (see below), whose sum is σ = 190475222. Its totient is φ = 187883040.

The previous prime is 189174683. The next prime is 189174731. The reversal of 189174721 is 127471981.

It can be written as a sum of positive squares in 3 ways, for example, as 497025 + 188677696 = 705^2 + 13736^2 .

It is not a de Polignac number, because 189174721 - 2⁷ = 189174593 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (189174731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 17941 + ... + 26461.

Almost surely, 2^189174721 is an apocalyptic number.

It is an amenable number.

189174721 is a deficient number, since it is larger than the sum of its proper divisors (1300501).

189174721 is an frugal number, since it uses more digits than its factorization.

189174721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8819 (or 8670 counting only the distinct ones).

The product of its digits is 28224, while the sum is 40.

The square root of 189174721 is about 13754.0801582658. The cubic root of 189174721 is about 574.0561412388.

The spelling of 189174721 in words is "one hundred eighty-nine million, one hundred seventy-four thousand, seven hundred twenty-one".