251131520206013 has 8 divisors (see below), whose sum is σ = 251230500423000. Its totient is φ = 251032548689728.

The previous prime is 251131520205997. The next prime is 251131520206051. The reversal of 251131520206013 is 310602025131152.

It can be written as a sum of positive squares in 4 ways, for example, as 108750233442244 + 142381286763769 = 10428338^2 + 11932363^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 251131520206013 - 2⁴ = 251131520205997 is a prime.

It is a super-2 number, since 2×251131520206013² (a number of 30 digits) 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 (251131520206813) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55867895 + ... + 60195387.

It is an arithmetic number, because the mean of its divisors is an integer number (31403812552875).

Almost surely, 2^{251131520206013} is an apocalyptic number.

It is an amenable number.

251131520206013 is a deficient number, since it is larger than the sum of its proper divisors (98980216987).

251131520206013 is a wasteful number, since it uses less digits than its factorization.

251131520206013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4350351.

The product of its (nonzero) digits is 10800, while the sum is 32.

Adding to 251131520206013 its reverse (310602025131152), we get a palindrome (561733545337165).

The spelling of 251131520206013 in words is "two hundred fifty-one trillion, one hundred thirty-one billion, five hundred twenty million, two hundred six thousand, thirteen".