251271717131 has 4 divisors (see below), whose sum is σ = 266052406392. Its totient is φ = 236491027872.

The previous prime is 251271717107. The next prime is 251271717139. The reversal of 251271717131 is 131717172152.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 251271717131 - 2²⁶ = 251204608267 is a prime.

It is a super-2 number, since 2×251271717131² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (251271717139) 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, 7390344605 + ... + 7390344638.

It is an arithmetic number, because the mean of its divisors is an integer number (66513101598).

Almost surely, 2^251271717131 is an apocalyptic number.

251271717131 is a deficient number, since it is larger than the sum of its proper divisors (14780689261).

251271717131 is a wasteful number, since it uses less digits than its factorization.

251271717131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14780689260.

The product of its digits is 20580, while the sum is 38.

Adding to 251271717131 its reverse (131717172152), we get a palindrome (382988889283).

The spelling of 251271717131 in words is "two hundred fifty-one billion, two hundred seventy-one million, seven hundred seventeen thousand, one hundred thirty-one".