251642312641 has 4 divisors (see below), whose sum is σ = 251826397632. Its totient is φ = 251458227652.

The previous prime is 251642312627. The next prime is 251642312707. The reversal of 251642312641 is 146213246152.

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 251642312641 - 2¹¹ = 251642310593 is a prime.

It is a super-2 number, since 2×251642312641² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 251642312641.

It is not an unprimeable number, because it can be changed into a prime (251642342641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 92040445 + ... + 92043178.

It is an arithmetic number, because the mean of its divisors is an integer number (62956599408).

Almost surely, 2^251642312641 is an apocalyptic number.

It is an amenable number.

251642312641 is a deficient number, since it is larger than the sum of its proper divisors (184084991).

251642312641 is a wasteful number, since it uses less digits than its factorization.

251642312641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 184084990.

The product of its digits is 69120, while the sum is 37.

Adding to 251642312641 its reverse (146213246152), we get a palindrome (397855558793).

The spelling of 251642312641 in words is "two hundred fifty-one billion, six hundred forty-two million, three hundred twelve thousand, six hundred forty-one".