251444113920 has 640 divisors, whose sum is σ = 915471406080. Its totient is φ = 66217181184.

The previous prime is 251444113891. The next prime is 251444113957. The reversal of 251444113920 is 29311444152.

251444113920 is a `hidden beast` number, since 2 + 514 + 4 + 4 + 1 + 139 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (640).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 543075609 + ... + 543076071.

It is an arithmetic number, because the mean of its divisors is an integer number (1430424072).

Almost surely, 2^251444113920 is an apocalyptic number.

251444113920 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 251444113920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (457735703040).

251444113920 is an abundant number, since it is smaller than the sum of its proper divisors (664027292160).

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

251444113920 is an frugal number, since it uses more digits than its factorization.

251444113920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 604 (or 570 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The spelling of 251444113920 in words is "two hundred fifty-one billion, four hundred forty-four million, one hundred thirteen thousand, nine hundred twenty".