164685681 has 48 divisors (see below), whose sum is σ = 268085376. Its totient is φ = 96864768.

The previous prime is 164685679. The next prime is 164685683. The reversal of 164685681 is 186586461.

It is an interprime number because it is at equal distance from previous prime (164685679) and next prime (164685683).

It is not a de Polignac number, because 164685681 - 2¹ = 164685679 is a prime.

It is a super-2 number, since 2×164685681² = 54242747052867522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (164685683) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 186066 + ... + 186948.

It is an arithmetic number, because the mean of its divisors is an integer number (5585112).

Almost surely, 2^164685681 is an apocalyptic number.

It is an amenable number.

164685681 is a deficient number, since it is larger than the sum of its proper divisors (103399695).

164685681 is a wasteful number, since it uses less digits than its factorization.

164685681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 982 (or 979 counting only the distinct ones).

The product of its digits is 276480, while the sum is 45.

The square root of 164685681 is about 12832.9918958908. The cubic root of 164685681 is about 548.1321552884.

The spelling of 164685681 in words is "one hundred sixty-four million, six hundred eighty-five thousand, six hundred eighty-one".