251240040000 has 840 divisors, whose sum is σ = 989045154240. Its totient is φ = 60673536000.

The previous prime is 251240039993. The next prime is 251240040067. The reversal of 251240040000 is 40042152.

251240040000 is a `hidden beast` number, since 25 + 1 + 240 + 0 + 400 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 157319202 + ... + 157320798.

Almost surely, 2^251240040000 is an apocalyptic number.

251240040000 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 251240040000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (494522577120).

251240040000 is an abundant number, since it is smaller than the sum of its proper divisors (737805114240).

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

251240040000 is a wasteful number, since it uses less digits than its factorization.

251240040000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1677 (or 1649 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 18.

Adding to 251240040000 its reverse (40042152), we get a palindrome (251280082152).

The spelling of 251240040000 in words is "two hundred fifty-one billion, two hundred forty million, forty thousand".