164946721 has 4 divisors (see below), whose sum is σ = 165784212. Its totient is φ = 164109232.

The previous prime is 164946689. The next prime is 164946739. The reversal of 164946721 is 127649461.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 138321121 + 26625600 = 11761^2 + 5160^2 .

It is a cyclic number.

It is not a de Polignac number, because 164946721 - 2⁵ = 164946689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (164946781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 418450 + ... + 418843.

It is an arithmetic number, because the mean of its divisors is an integer number (41446053).

Almost surely, 2^164946721 is an apocalyptic number.

It is an amenable number.

164946721 is a deficient number, since it is larger than the sum of its proper divisors (837491).

164946721 is an equidigital number, since it uses as much as digits as its factorization.

164946721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 837490.

The product of its digits is 72576, while the sum is 40.

The square root of 164946721 is about 12843.1585289601. The cubic root of 164946721 is about 548.4216135327.

The spelling of 164946721 in words is "one hundred sixty-four million, nine hundred forty-six thousand, seven hundred twenty-one".