189745021 has 2 divisors, whose sum is σ = 189745022. Its totient is φ = 189745020.

The previous prime is 189744983. The next prime is 189745027. The reversal of 189745021 is 120547981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 158508100 + 31236921 = 12590^2 + 5589^2 .

It is a cyclic number.

It is not a de Polignac number, because 189745021 - 2¹³ = 189736829 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (189745027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94872510 + 94872511.

It is an arithmetic number, because the mean of its divisors is an integer number (94872511).

Almost surely, 2^189745021 is an apocalyptic number.

It is an amenable number.

189745021 is a deficient number, since it is larger than the sum of its proper divisors (1).

189745021 is an equidigital number, since it uses as much as digits as its factorization.

189745021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20160, while the sum is 37.

The square root of 189745021 is about 13774.7965865199. The cubic root of 189745021 is about 574.6324264493.

The spelling of 189745021 in words is "one hundred eighty-nine million, seven hundred forty-five thousand, twenty-one".