191712989 has 8 divisors (see below), whose sum is σ = 207060000. Its totient is φ = 176451696.

The previous prime is 191712971. The next prime is 191712991. The reversal of 191712989 is 989217191.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 191712989 - 2⁸ = 191712733 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 (191712919) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16739 + ... + 25760.

It is an arithmetic number, because the mean of its divisors is an integer number (25882500).

Almost surely, 2^191712989 is an apocalyptic number.

It is an amenable number.

191712989 is a deficient number, since it is larger than the sum of its proper divisors (15347011).

191712989 is a wasteful number, since it uses less digits than its factorization.

191712989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42859.

The product of its digits is 81648, while the sum is 47.

The square root of 191712989 is about 13846.0459698789. The cubic root of 191712989 is about 576.6122253987.

The spelling of 191712989 in words is "one hundred ninety-one million, seven hundred twelve thousand, nine hundred eighty-nine".