251287920 has 400 divisors, whose sum is σ = 995665440. Its totient is φ = 58226688.

The previous prime is 251287913. The next prime is 251287921. The reversal of 251287920 is 29782152.

251287920 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251287921) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 1600482 + ... + 1600638.

Almost surely, 2^251287920 is an apocalyptic number.

251287920 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 251287920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (497832720).

251287920 is an abundant number, since it is smaller than the sum of its proper divisors (744377520).

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

251287920 is a wasteful number, since it uses less digits than its factorization.

251287920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214 (or 199 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 251287920 is about 15852.0635880632. The cubic root of 251287920 is about 631.0404575883.

The spelling of 251287920 in words is "two hundred fifty-one million, two hundred eighty-seven thousand, nine hundred twenty".