251872140 has 96 divisors (see below), whose sum is σ = 767551680. Its totient is φ = 61341696.

The previous prime is 251872139. The next prime is 251872147. The reversal of 251872140 is 41278152.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 251872098 and 251872107.

It is not an unprimeable number, because it can be changed into a prime (251872147) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 73996 + ... + 77324.

It is an arithmetic number, because the mean of its divisors is an integer number (7995330).

Almost surely, 2^251872140 is an apocalyptic number.

251872140 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 251872140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (383775840).

251872140 is an abundant number, since it is smaller than the sum of its proper divisors (515679540).

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

251872140 is a wasteful number, since it uses less digits than its factorization.

251872140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3451 (or 3449 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 30.

The square root of 251872140 is about 15870.4801439654. The cubic root of 251872140 is about 631.5291150083.

The spelling of 251872140 in words is "two hundred fifty-one million, eight hundred seventy-two thousand, one hundred forty".