189964871 has 2 divisors, whose sum is σ = 189964872. Its totient is φ = 189964870.

The previous prime is 189964867. The next prime is 189964903. The reversal of 189964871 is 178469981.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 189964871 - 2² = 189964867 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (189964811) 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 as a sum of consecutive naturals, namely, 94982435 + 94982436.

It is an arithmetic number, because the mean of its divisors is an integer number (94982436).

Almost surely, 2^189964871 is an apocalyptic number.

189964871 is a deficient number, since it is larger than the sum of its proper divisors (1).

189964871 is an equidigital number, since it uses as much as digits as its factorization.

189964871 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 870912, while the sum is 53.

The square root of 189964871 is about 13782.7744304258. The cubic root of 189964871 is about 574.8542753589.

The spelling of 189964871 in words is "one hundred eighty-nine million, nine hundred sixty-four thousand, eight hundred seventy-one".