191664972 has 36 divisors (see below), whose sum is σ = 487586736. Its totient is φ = 63479520.

The previous prime is 191664943. The next prime is 191664983. The reversal of 191664972 is 279466191.

191664972 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×191664972² = 73470922983521568, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11304 + ... + 22607.

It is an arithmetic number, because the mean of its divisors is an integer number (13544076).

Almost surely, 2^191664972 is an apocalyptic number.

191664972 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

191664972 is the 11304-th pentagonal number.

It is an amenable number.

191664972 is an abundant number, since it is smaller than the sum of its proper divisors (295921764).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

191664972 is a wasteful number, since it uses less digits than its factorization.

191664972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34078 (or 34073 counting only the distinct ones).

The product of its digits is 163296, while the sum is 45.

The square root of 191664972 is about 13844.3119005605. The cubic root of 191664972 is about 576.5640813802.

The spelling of 191664972 in words is "one hundred ninety-one million, six hundred sixty-four thousand, nine hundred seventy-two".