251850638340 has 576 divisors, whose sum is σ = 954699153408. Its totient is φ = 54512870400.

The previous prime is 251850638321. The next prime is 251850638341. The reversal of 251850638340 is 43836058152.

251850638340 is a `hidden beast` number, since 2 + 5 + 1 + 8 + 5 + 0 + 638 + 3 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (251850638341) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 49564600 + ... + 49569680.

It is an arithmetic number, because the mean of its divisors is an integer number (1657463808).

Almost surely, 2^251850638340 is an apocalyptic number.

251850638340 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 251850638340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (477349576704).

251850638340 is an abundant number, since it is smaller than the sum of its proper divisors (702848515068).

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

251850638340 is a wasteful number, since it uses less digits than its factorization.

251850638340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5190 (or 5176 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 45.

The spelling of 251850638340 in words is "two hundred fifty-one billion, eight hundred fifty million, six hundred thirty-eight thousand, three hundred forty".