251352561 has 4 divisors (see below), whose sum is σ = 335136752. Its totient is φ = 167568372.

The previous prime is 251352551. The next prime is 251352589. The reversal of 251352561 is 165253152.

It is a happy number.

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 251352561 - 2⁵ = 251352529 is a prime.

It is a Duffinian number.

It is a zygodrome in base 11.

It is not an unprimeable number, because it can be changed into a prime (251352551) 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, 41892091 + ... + 41892096.

It is an arithmetic number, because the mean of its divisors is an integer number (83784188).

Almost surely, 2^251352561 is an apocalyptic number.

It is an amenable number.

251352561 is a deficient number, since it is larger than the sum of its proper divisors (83784191).

251352561 is an equidigital number, since it uses as much as digits as its factorization.

251352561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83784190.

The product of its digits is 9000, while the sum is 30.

The square root of 251352561 is about 15854.1023397731. The cubic root of 251352561 is about 631.0945623101.

The spelling of 251352561 in words is "two hundred fifty-one million, three hundred fifty-two thousand, five hundred sixty-one".