251921940480 has 960 divisors, whose sum is σ = 1046363028480. Its totient is φ = 56311676928.

The previous prime is 251921940469. The next prime is 251921940511. The reversal of 251921940480 is 84049129152.

It is a happy number.

251921940480 is a `hidden beast` number, since 2 + 519 + 2 + 1 + 94 + 0 + 48 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (960).

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 820592487 + ... + 820592793.

It is an arithmetic number, because the mean of its divisors is an integer number (1089961488).

Almost surely, 2^251921940480 is an apocalyptic number.

251921940480 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 251921940480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (523181514240).

251921940480 is an abundant number, since it is smaller than the sum of its proper divisors (794441088000).

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

251921940480 is an equidigital number, since it uses as much as digits as its factorization.

251921940480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 409 (or 377 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 45.

The spelling of 251921940480 in words is "two hundred fifty-one billion, nine hundred twenty-one million, nine hundred forty thousand, four hundred eighty".