1251356400 has 720 divisors, whose sum is σ = 5526503424. Its totient is φ = 255467520.

The previous prime is 1251356399. The next prime is 1251356419. The reversal of 1251356400 is 46531521.

1251356400 is a `hidden beast` number, since 1 + 2 + 5 + 13 + 5 + 640 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 9853137 + ... + 9853263.

Almost surely, 2^1251356400 is an apocalyptic number.

1251356400 is a gapful number since it is divisible by the number (10) 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 1251356400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2763251712).

1251356400 is an abundant number, since it is smaller than the sum of its proper divisors (4275147024).

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

1251356400 is a wasteful number, since it uses less digits than its factorization.

1251356400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198 (or 184 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 1251356400 is about 35374.5162511094. The cubic root of 1251356400 is about 1077.6068408618.

Adding to 1251356400 its reverse (46531521), we get a palindrome (1297887921).

The spelling of 1251356400 in words is "one billion, two hundred fifty-one million, three hundred fifty-six thousand, four hundred".