251051400240 has 160 divisors (see below), whose sum is σ = 780782526720. Its totient is φ = 66730417152.

The previous prime is 251051400227. The next prime is 251051400241. The reversal of 251051400240 is 42004150152.

251051400240 is digitally balanced in base 2, 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 (24).

It is a self number, because there is not a number n which added to its sum of digits gives 251051400240.

It is not an unprimeable number, because it can be changed into a prime (251051400241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 150599887 + ... + 150601553.

It is an arithmetic number, because the mean of its divisors is an integer number (4879890792).

Almost surely, 2^251051400240 is an apocalyptic number.

251051400240 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 251051400240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (390391263360).

251051400240 is an abundant number, since it is smaller than the sum of its proper divisors (529731126480).

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

251051400240 is a wasteful number, since it uses less digits than its factorization.

251051400240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3339 (or 3333 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 24.

Adding to 251051400240 its reverse (42004150152), we get a palindrome (293055550392).

The spelling of 251051400240 in words is "two hundred fifty-one billion, fifty-one million, four hundred thousand, two hundred forty".