164520391 has 6 divisors (see below), whose sum is σ = 191380920. Its totient is φ = 141017436.

The previous prime is 164520383. The next prime is 164520397. The reversal of 164520391 is 193025461.

It is not a de Polignac number, because 164520391 - 2³ = 164520383 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 (164520397) 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, 1678731 + ... + 1678828.

It is an arithmetic number, because the mean of its divisors is an integer number (31896820).

Almost surely, 2^164520391 is an apocalyptic number.

164520391 is a deficient number, since it is larger than the sum of its proper divisors (26860529).

164520391 is an equidigital number, since it uses as much as digits as its factorization.

164520391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3357573 (or 3357566 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 164520391 is about 12826.5502376906. The cubic root of 164520391 is about 547.9487127220.

The spelling of 164520391 in words is "one hundred sixty-four million, five hundred twenty thousand, three hundred ninety-one".