251553303240 has 128 divisors (see below), whose sum is σ = 765157536000. Its totient is φ = 66153185280.

The previous prime is 251553303181. The next prime is 251553303277. The reversal of 251553303240 is 42303355152.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2936536 + ... + 3020984.

It is an arithmetic number, because the mean of its divisors is an integer number (5977793250).

Almost surely, 2^251553303240 is an apocalyptic number.

251553303240 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 251553303240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (382578768000).

251553303240 is an abundant number, since it is smaller than the sum of its proper divisors (513604232760).

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

251553303240 is a wasteful number, since it uses less digits than its factorization.

251553303240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84807 (or 84803 counting only the distinct ones).

The product of its (nonzero) digits is 54000, while the sum is 33.

Adding to 251553303240 its reverse (42303355152), we get a palindrome (293856658392).

The spelling of 251553303240 in words is "two hundred fifty-one billion, five hundred fifty-three million, three hundred three thousand, two hundred forty".