252640137 has 4 divisors (see below), whose sum is σ = 336853520. Its totient is φ = 168426756.

The previous prime is 252640121. The next prime is 252640159. The reversal of 252640137 is 731046252.

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 not a de Polignac number, because 252640137 - 2⁴ = 252640121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (252640337) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42106687 + ... + 42106692.

It is an arithmetic number, because the mean of its divisors is an integer number (84213380).

Almost surely, 2^252640137 is an apocalyptic number.

It is an amenable number.

252640137 is a deficient number, since it is larger than the sum of its proper divisors (84213383).

252640137 is an equidigital number, since it uses as much as digits as its factorization.

252640137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84213382.

The product of its (nonzero) digits is 10080, while the sum is 30.

The square root of 252640137 is about 15894.6574986692. The cubic root of 252640137 is about 632.1703402742.

Adding to 252640137 its reverse (731046252), we get a palindrome (983686389).

The spelling of 252640137 in words is "two hundred fifty-two million, six hundred forty thousand, one hundred thirty-seven".