251055021400 has 96 divisors (see below), whose sum is σ = 596495304000. Its totient is φ = 98223851520.

The previous prime is 251055021397. The next prime is 251055021467. The reversal of 251055021400 is 4120550152.

251055021400 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16809136 + ... + 16824064.

It is an arithmetic number, because the mean of its divisors is an integer number (6213492750).

Almost surely, 2^251055021400 is an apocalyptic number.

251055021400 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 251055021400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (298247652000).

251055021400 is an abundant number, since it is smaller than the sum of its proper divisors (345440282600).

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

251055021400 is a wasteful number, since it uses less digits than its factorization.

251055021400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16781 (or 16772 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 25.

Adding to 251055021400 its reverse (4120550152), we get a palindrome (255175571552).

The spelling of 251055021400 in words is "two hundred fifty-one billion, fifty-five million, twenty-one thousand, four hundred".