251406794240 has 160 divisors (see below), whose sum is σ = 690150827520. Its totient is φ = 86040059904.

The previous prime is 251406794213. The next prime is 251406794299. The reversal of 251406794240 is 42497604152.

It is a tau number, because it is divible by the number of its divisors (160).

It is a junction number, because it is equal to n+sod(n) for n = 251406794191 and 251406794200.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10076501 + ... + 10101419.

It is an arithmetic number, because the mean of its divisors is an integer number (4313442672).

Almost surely, 2^251406794240 is an apocalyptic number.

251406794240 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 251406794240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (345075413760).

251406794240 is an abundant number, since it is smaller than the sum of its proper divisors (438744033280).

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

251406794240 is an equidigital number, since it uses as much as digits as its factorization.

251406794240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25512 (or 25496 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 44.

The spelling of 251406794240 in words is "two hundred fifty-one billion, four hundred six million, seven hundred ninety-four thousand, two hundred forty".