2556897840 has 200 divisors, whose sum is σ = 10149305760. Its totient is φ = 584423424.

The previous prime is 2556897829. The next prime is 2556897851. The reversal of 2556897840 is 487986552.

2556897840 is a `hidden beast` number, since 2 + 5 + 568 + 9 + 78 + 4 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (2556897829) and next prime (2556897851).

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

It is an unprimeable number.

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 39 ways as a sum of consecutive naturals, for example, 17176 + ... + 73544.

Almost surely, 2^2556897840 is an apocalyptic number.

2556897840 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 2556897840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5074652880).

2556897840 is an abundant number, since it is smaller than the sum of its proper divisors (7592407920).

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

2556897840 is a wasteful number, since it uses less digits than its factorization.

2556897840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56401 (or 56386 counting only the distinct ones).

The product of its (nonzero) digits is 4838400, while the sum is 54.

The square root of 2556897840 is about 50565.7773597915. Note that the first 3 decimals coincide. The cubic root of 2556897840 is about 1367.4279695179.

The spelling of 2556897840 in words is "two billion, five hundred fifty-six million, eight hundred ninety-seven thousand, eight hundred forty".