191664147 has 6 divisors (see below), whose sum is σ = 255584172. Its totient is φ = 127760112.

The previous prime is 191664139. The next prime is 191664157. The reversal of 191664147 is 741466191.

It is not a de Polignac number, because 191664147 - 2³ = 191664139 is a prime.

It is not an unprimeable number, because it can be changed into a prime (191664127) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 19983 + ... + 27975.

It is an arithmetic number, because the mean of its divisors is an integer number (42597362).

Almost surely, 2^191664147 is an apocalyptic number.

191664147 is a deficient number, since it is larger than the sum of its proper divisors (63920025).

191664147 is an frugal number, since it uses more digits than its factorization.

191664147 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15989 (or 7996 counting only the distinct ones).

The product of its digits is 36288, while the sum is 39.

The square root of 191664147 is about 13844.2821048980. The cubic root of 191664147 is about 576.5632541276.

The spelling of 191664147 in words is "one hundred ninety-one million, six hundred sixty-four thousand, one hundred forty-seven".