1256990400 has 504 divisors, whose sum is σ = 4797911664. Its totient is φ = 323481600.

The previous prime is 1256990377. The next prime is 1256990407. The reversal of 1256990400 is 40996521.

1256990400 is a `hidden beast` number, since 1 + 2 + 569 + 90 + 4 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (1256990407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 20606370 + ... + 20606430.

It is an arithmetic number, because the mean of its divisors is an integer number (9519666).

Almost surely, 2^1256990400 is an apocalyptic number.

1256990400 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 1256990400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2398955832).

1256990400 is an abundant number, since it is smaller than the sum of its proper divisors (3540921264).

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

1256990400 is an equidigital number, since it uses as much as digits as its factorization.

1256990400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151 (or 124 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The square root of 1256990400 is about 35454.0604162626. The cubic root of 1256990400 is about 1079.2216614209.

The spelling of 1256990400 in words is "one billion, two hundred fifty-six million, nine hundred ninety thousand, four hundred".