189921401 has 2 divisors, whose sum is σ = 189921402. Its totient is φ = 189921400.

The previous prime is 189921383. The next prime is 189921427. The reversal of 189921401 is 104129981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 172239376 + 17682025 = 13124^2 + 4205^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-189921401 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (189921001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94960700 + 94960701.

It is an arithmetic number, because the mean of its divisors is an integer number (94960701).

Almost surely, 2^189921401 is an apocalyptic number.

It is an amenable number.

189921401 is a deficient number, since it is larger than the sum of its proper divisors (1).

189921401 is an equidigital number, since it uses as much as digits as its factorization.

189921401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 35.

The square root of 189921401 is about 13781.1973717816. The cubic root of 189921401 is about 574.8104237043.

The spelling of 189921401 in words is "one hundred eighty-nine million, nine hundred twenty-one thousand, four hundred one".