251231402113111 has 4 divisors (see below), whose sum is σ = 287121602414992. Its totient is φ = 215341201811232.

The previous prime is 251231402113099. The next prime is 251231402113127. The reversal of 251231402113111 is 111311204132152.

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

It is a de Polignac number, because none of the positive numbers 2^k-251231402113111 is a prime.

It is a super-3 number, since 3×251231402113111³ (a number of 44 digits) contains 333 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 251231402113111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251231402113141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17945100150930 + ... + 17945100150943.

It is an arithmetic number, because the mean of its divisors is an integer number (71780400603748).

Almost surely, 2^{251231402113111} is an apocalyptic number.

251231402113111 is a deficient number, since it is larger than the sum of its proper divisors (35890200301881).

251231402113111 is an equidigital number, since it uses as much as digits as its factorization.

251231402113111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35890200301880.

The product of its (nonzero) digits is 1440, while the sum is 28.

Adding to 251231402113111 its reverse (111311204132152), we get a palindrome (362542606245263).

The spelling of 251231402113111 in words is "two hundred fifty-one trillion, two hundred thirty-one billion, four hundred two million, one hundred thirteen thousand, one hundred eleven".