251230111540 has 12 divisors (see below), whose sum is σ = 527583234276. Its totient is φ = 100492044608.

The previous prime is 251230111537. The next prime is 251230111549. The reversal of 251230111540 is 45111032152.

It can be written as a sum of positive squares in 2 ways, for example, as 76409122084 + 174820989456 = 276422^2 + 418116^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251230111549) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6280752769 + ... + 6280752808.

It is an arithmetic number, because the mean of its divisors is an integer number (43965269523).

Almost surely, 2^251230111540 is an apocalyptic number.

251230111540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

251230111540 is an abundant number, since it is smaller than the sum of its proper divisors (276353122736).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

251230111540 is a wasteful number, since it uses less digits than its factorization.

251230111540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12561505586 (or 12561505584 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 25.

Adding to 251230111540 its reverse (45111032152), we get a palindrome (296341143692).

The spelling of 251230111540 in words is "two hundred fifty-one billion, two hundred thirty million, one hundred eleven thousand, five hundred forty".