189722921 has 2 divisors, whose sum is σ = 189722922. Its totient is φ = 189722920.

The previous prime is 189722861. The next prime is 189722947. The reversal of 189722921 is 129227981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 140090896 + 49632025 = 11836^2 + 7045^2 .

It is a cyclic number.

It is not a de Polignac number, because 189722921 - 2⁶ = 189722857 is a prime.

It is not a weakly prime, because it can be changed into another prime (185722921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94861460 + 94861461.

It is an arithmetic number, because the mean of its divisors is an integer number (94861461).

Almost surely, 2^189722921 is an apocalyptic number.

It is an amenable number.

189722921 is a deficient number, since it is larger than the sum of its proper divisors (1).

189722921 is an equidigital number, since it uses as much as digits as its factorization.

189722921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36288, while the sum is 41.

The square root of 189722921 is about 13773.9943734561. The cubic root of 189722921 is about 574.6101160357.

The spelling of 189722921 in words is "one hundred eighty-nine million, seven hundred twenty-two thousand, nine hundred twenty-one".