252665581 has 4 divisors (see below), whose sum is σ = 288760672. Its totient is φ = 216570492.

The previous prime is 252665579. The next prime is 252665587. The reversal of 252665581 is 185566252.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 252665581 - 2¹ = 252665579 is a prime.

It is a super-2 number, since 2×252665581² = 127679791644135122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (252665587) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18047535 + ... + 18047548.

It is an arithmetic number, because the mean of its divisors is an integer number (72190168).

Almost surely, 2^252665581 is an apocalyptic number.

It is an amenable number.

252665581 is a deficient number, since it is larger than the sum of its proper divisors (36095091).

252665581 is an equidigital number, since it uses as much as digits as its factorization.

252665581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36095090.

The product of its digits is 144000, while the sum is 40.

The square root of 252665581 is about 15895.4578732417. The cubic root of 252665581 is about 632.1915620304.

The spelling of 252665581 in words is "two hundred fifty-two million, six hundred sixty-five thousand, five hundred eighty-one".