251944266240 has 560 divisors, whose sum is σ = 913689520128. Its totient is φ = 66593415168.

The previous prime is 251944266227. The next prime is 251944266247. The reversal of 251944266240 is 42662449152.

It is a happy number.

251944266240 is a `hidden beast` number, since 2 + 5 + 19 + 4 + 4 + 2 + 6 + 624 + 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 (251944266247) by changing a digit.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 237011949 + ... + 237013011.

Almost surely, 2^251944266240 is an apocalyptic number.

251944266240 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 251944266240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (456844760064).

251944266240 is an abundant number, since it is smaller than the sum of its proper divisors (661745253888).

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

251944266240 is an equidigital number, since it uses as much as digits as its factorization.

251944266240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1231 (or 1200 counting only the distinct ones).

The product of its (nonzero) digits is 829440, while the sum is 45.

The spelling of 251944266240 in words is "two hundred fifty-one billion, nine hundred forty-four million, two hundred sixty-six thousand, two hundred forty".