251998320 has 160 divisors (see below), whose sum is σ = 907799040. Its totient is φ = 56632320.

The previous prime is 251998309. The next prime is 251998321. The reversal of 251998320 is 23899152.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251998321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 101251 + ... + 103709.

It is an arithmetic number, because the mean of its divisors is an integer number (5673744).

Almost surely, 2^251998320 is an apocalyptic number.

251998320 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 251998320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (453899520).

251998320 is an abundant number, since it is smaller than the sum of its proper divisors (655800720).

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

251998320 is a wasteful number, since it uses less digits than its factorization.

251998320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2543 (or 2537 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 39.

The square root of 251998320 is about 15874.4549512731. The cubic root of 251998320 is about 631.6345561271.

The spelling of 251998320 in words is "two hundred fifty-one million, nine hundred ninety-eight thousand, three hundred twenty".