164309581 has 2 divisors, whose sum is σ = 164309582. Its totient is φ = 164309580.

The previous prime is 164309567. The next prime is 164309611. The reversal of 164309581 is 185903461.

164309581 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 150552900 + 13756681 = 12270^2 + 3709^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-164309581 is a prime.

It is a super-2 number, since 2×164309581² = 53995276816791122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 164309581.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (164309531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82154790 + 82154791.

It is an arithmetic number, because the mean of its divisors is an integer number (82154791).

Almost surely, 2^164309581 is an apocalyptic number.

It is an amenable number.

164309581 is a deficient number, since it is larger than the sum of its proper divisors (1).

164309581 is an equidigital number, since it uses as much as digits as its factorization.

164309581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 164309581 is about 12818.3298834130. The cubic root of 164309581 is about 547.7145726648.

The spelling of 164309581 in words is "one hundred sixty-four million, three hundred nine thousand, five hundred eighty-one".