251013219840 has 800 divisors, whose sum is σ = 983070722304. Its totient is φ = 60940615680.

The previous prime is 251013219833. The next prime is 251013219883. The reversal of 251013219840 is 48912310152.

251013219840 is a `hidden beast` number, since 2 + 510 + 13 + 2 + 1 + 98 + 40 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 251013219795 and 251013219804.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 109277572 + ... + 109279868.

Almost surely, 2^251013219840 is an apocalyptic number.

251013219840 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 251013219840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (491535361152).

251013219840 is an abundant number, since it is smaller than the sum of its proper divisors (732057502464).

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

251013219840 is a wasteful number, since it uses less digits than its factorization.

251013219840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2380 (or 2355 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

Adding to 251013219840 its reverse (48912310152), we get a palindrome (299925529992).

The spelling of 251013219840 in words is "two hundred fifty-one billion, thirteen million, two hundred nineteen thousand, eight hundred forty".