251780020 has 48 divisors (see below), whose sum is σ = 559641600. Its totient is φ = 94884480.

The previous prime is 251780003. The next prime is 251780027. The reversal of 251780020 is 20087152.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251780027) 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, 70846 + ... + 74314.

It is an arithmetic number, because the mean of its divisors is an integer number (11659200).

Almost surely, 2^251780020 is an apocalyptic number.

251780020 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 251780020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (279820800).

251780020 is an abundant number, since it is smaller than the sum of its proper divisors (307861580).

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

251780020 is a wasteful number, since it uses less digits than its factorization.

251780020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3688 (or 3686 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 25.

The square root of 251780020 is about 15867.5776349133. The cubic root of 251780020 is about 631.4521135636.

The spelling of 251780020 in words is "two hundred fifty-one million, seven hundred eighty thousand, twenty".