251121305231 has 8 divisors (see below), whose sum is σ = 255533700240. Its totient is φ = 246714113728.

The previous prime is 251121305213. The next prime is 251121305233. The reversal of 251121305231 is 132503121152.

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 251121305231 - 2¹⁰ = 251121304207 is a prime.

It is a super-2 number, since 2×251121305231² (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 251121305231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251121305233) 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, 1203446 + ... + 1396611.

It is an arithmetic number, because the mean of its divisors is an integer number (31941712530).

Almost surely, 2^251121305231 is an apocalyptic number.

251121305231 is a deficient number, since it is larger than the sum of its proper divisors (4412395009).

251121305231 is a wasteful number, since it uses less digits than its factorization.

251121305231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2601753.

The product of its (nonzero) digits is 1800, while the sum is 26.

Adding to 251121305231 its reverse (132503121152), we get a palindrome (383624426383).

The spelling of 251121305231 in words is "two hundred fifty-one billion, one hundred twenty-one million, three hundred five thousand, two hundred thirty-one".