251605480 has 64 divisors (see below), whose sum is σ = 657636480. Its totient is φ = 84844800.

The previous prime is 251605399. The next prime is 251605481. The reversal of 251605480 is 84506152.

It is not an unprimeable number, because it can be changed into a prime (251605481) 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, 9715 + ... + 24445.

It is an arithmetic number, because the mean of its divisors is an integer number (10275570).

Almost surely, 2^251605480 is an apocalyptic number.

251605480 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 251605480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (328818240).

251605480 is an abundant number, since it is smaller than the sum of its proper divisors (406031000).

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

251605480 is a wasteful number, since it uses less digits than its factorization.

251605480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14810 (or 14806 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 31.

The square root of 251605480 is about 15862.0767871045. The cubic root of 251605480 is about 631.3061672076.

The spelling of 251605480 in words is "two hundred fifty-one million, six hundred five thousand, four hundred eighty".