251113128 has 64 divisors (see below), whose sum is σ = 719280000. Its totient is φ = 71565312.

The previous prime is 251113123. The next prime is 251113129. The reversal of 251113128 is 821311152.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a junction number, because it is equal to n+sod(n) for n = 251113098 and 251113107.

It is not an unprimeable number, because it can be changed into a prime (251113123) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 73768 + ... + 77096.

It is an arithmetic number, because the mean of its divisors is an integer number (11238750).

Almost surely, 2^251113128 is an apocalyptic number.

251113128 is a gapful number since it is divisible by the number (28) 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 251113128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (359640000).

251113128 is an abundant number, since it is smaller than the sum of its proper divisors (468166872).

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

251113128 is a wasteful number, since it uses less digits than its factorization.

251113128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3794 (or 3790 counting only the distinct ones).

The product of its digits is 480, while the sum is 24.

The square root of 251113128 is about 15846.5494035768. The cubic root of 251113128 is about 630.8941096486.

The spelling of 251113128 in words is "two hundred fifty-one million, one hundred thirteen thousand, one hundred twenty-eight".