251172978408 has 576 divisors, whose sum is σ = 805595281920. Its totient is φ = 72748368000.

The previous prime is 251172978403. The next prime is 251172978409. The reversal of 251172978408 is 804879271152.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (251172978403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 1663397133 + ... + 1663397283.

It is an arithmetic number, because the mean of its divisors is an integer number (1398602920).

Almost surely, 2^251172978408 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 251172978408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (402797640960).

251172978408 is an abundant number, since it is smaller than the sum of its proper divisors (554422303512).

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

251172978408 is a wasteful number, since it uses less digits than its factorization.

251172978408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 302 (or 277 counting only the distinct ones).

The product of its (nonzero) digits is 2257920, while the sum is 54.

The spelling of 251172978408 in words is "two hundred fifty-one billion, one hundred seventy-two million, nine hundred seventy-eight thousand, four hundred eight".