164242561 has 12 divisors (see below), whose sum is σ = 194193300. Its totient is φ = 138468960.

The previous prime is 164242543. The next prime is 164242571. The reversal of 164242561 is 165242461.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 23464336 + 140778225 = 4844^2 + 11865^2 .

It is a de Polignac number, because none of the positive numbers 2^k-164242561 is a prime.

It is not an unprimeable number, because it can be changed into a prime (164242571) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 24486 + ... + 30463.

It is an arithmetic number, because the mean of its divisors is an integer number (16182775).

Almost surely, 2^164242561 is an apocalyptic number.

It is an amenable number.

164242561 is a deficient number, since it is larger than the sum of its proper divisors (29950739).

164242561 is an equidigital number, since it uses as much as digits as its factorization.

164242561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55024 (or 55017 counting only the distinct ones).

The product of its digits is 11520, while the sum is 31.

The square root of 164242561 is about 12815.7153916588. The cubic root of 164242561 is about 547.6400936996.

The spelling of 164242561 in words is "one hundred sixty-four million, two hundred forty-two thousand, five hundred sixty-one".