164675721 has 48 divisors (see below), whose sum is σ = 265446720. Its totient is φ = 90478080.

The previous prime is 164675713. The next prime is 164675723. The reversal of 164675721 is 127576461.

It is not a de Polignac number, because 164675721 - 2³ = 164675713 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 164675721.

It is not an unprimeable number, because it can be changed into a prime (164675723) 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, 536250 + ... + 536556.

It is an arithmetic number, because the mean of its divisors is an integer number (5530140).

Almost surely, 2^164675721 is an apocalyptic number.

It is an amenable number.

164675721 is a deficient number, since it is larger than the sum of its proper divisors (100770999).

164675721 is a wasteful number, since it uses less digits than its factorization.

164675721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 454 (or 447 counting only the distinct ones).

The product of its digits is 70560, while the sum is 39.

The square root of 164675721 is about 12832.6038277506. The cubic root of 164675721 is about 548.1211049322.

The spelling of 164675721 in words is "one hundred sixty-four million, six hundred seventy-five thousand, seven hundred twenty-one".