251312135000 has 80 divisors (see below), whose sum is σ = 590170772400. Its totient is φ = 100294992000.

The previous prime is 251312134973. The next prime is 251312135003. The reversal of 251312135000 is 531213152.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251312135003) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2137754 + ... + 2252246.

It is an arithmetic number, because the mean of its divisors is an integer number (7377134655).

Almost surely, 2^251312135000 is an apocalyptic number.

251312135000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 251312135000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (295085386200).

251312135000 is an abundant number, since it is smaller than the sum of its proper divisors (338858637400).

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

251312135000 is a wasteful number, since it uses less digits than its factorization.

251312135000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114958 (or 114939 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 23.

Adding to 251312135000 its reverse (531213152), we get a palindrome (251843348152).

The spelling of 251312135000 in words is "two hundred fifty-one billion, three hundred twelve million, one hundred thirty-five thousand".