164066391 has 10 divisors (see below), whose sum is σ = 245086952. Its totient is φ = 109377540.

The previous prime is 164066377. The next prime is 164066407. The reversal of 164066391 is 193660461.

164066391 is a `hidden beast` number, since 1 + 640 + 6 + 6 + 3 + 9 + 1 = 666.

It is not a de Polignac number, because 164066391 - 2⁶ = 164066327 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 (164066321) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 1012675 + ... + 1012836.

Almost surely, 2^164066391 is an apocalyptic number.

164066391 is a deficient number, since it is larger than the sum of its proper divisors (81020561).

164066391 is an equidigital number, since it uses as much as digits as its factorization.

164066391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2025523 (or 2025514 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

The square root of 164066391 is about 12808.8403456363. The cubic root of 164066391 is about 547.4442202509. Note that the first 3 decimals are identical.

The spelling of 164066391 in words is "one hundred sixty-four million, sixty-six thousand, three hundred ninety-one".