1271398400 has 120 divisors (see below), whose sum is σ = 3185570850. Its totient is φ = 503316480.

The previous prime is 1271398379. The next prime is 1271398409. The reversal of 1271398400 is 48931721.

1271398400 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 912523264 + 358875136 = 30208^2 + 18944^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1271398409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 13107152 + ... + 13107248.

Almost surely, 2^1271398400 is an apocalyptic number.

1271398400 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 1271398400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1592785425).

1271398400 is an abundant number, since it is smaller than the sum of its proper divisors (1914172450).

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

1271398400 is an frugal number, since it uses more digits than its factorization.

1271398400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145 (or 104 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 1271398400 is about 35656.6739895913. The cubic root of 1271398400 is about 1083.3294600782.

The spelling of 1271398400 in words is "one billion, two hundred seventy-one million, three hundred ninety-eight thousand, four hundred".