189699991 has 16 divisors (see below), whose sum is σ = 223776000. Its totient is φ = 159118848.

The previous prime is 189699977. The next prime is 189700019. The reversal of 189699991 is 199996981.

It is a cyclic number.

It is not a de Polignac number, because 189699991 - 2⁵ = 189699959 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 (189699901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8391 + ... + 21208.

It is an arithmetic number, because the mean of its divisors is an integer number (13986000).

Almost surely, 2^189699991 is an apocalyptic number.

189699991 is a deficient number, since it is larger than the sum of its proper divisors (34076009).

189699991 is a wasteful number, since it uses less digits than its factorization.

189699991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29658.

The product of its digits is 2834352, while the sum is 61.

The square root of 189699991 is about 13773.1619826386. The cubic root of 189699991 is about 574.5869658882.

The spelling of 189699991 in words is "one hundred eighty-nine million, six hundred ninety-nine thousand, nine hundred ninety-one".