251680380 has 96 divisors (see below), whose sum is σ = 812657664. Its totient is φ = 57007104.

The previous prime is 251680379. The next prime is 251680381. The reversal of 251680380 is 83086152.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (251680379) and next prime (251680381).

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251680381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 44809 + ... + 50111.

It is an arithmetic number, because the mean of its divisors is an integer number (8465184).

Almost surely, 2^251680380 is an apocalyptic number.

251680380 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 251680380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (406328832).

251680380 is an abundant number, since it is smaller than the sum of its proper divisors (560977284).

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

251680380 is a wasteful number, since it uses less digits than its factorization.

251680380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5435 (or 5433 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 33.

The square root of 251680380 is about 15864.4375885185. The cubic root of 251680380 is about 631.3688051393.

The spelling of 251680380 in words is "two hundred fifty-one million, six hundred eighty thousand, three hundred eighty".