2556561020 has 96 divisors (see below), whose sum is σ = 5894441280. Its totient is φ = 931257600.

The previous prime is 2556560987. The next prime is 2556561127. The reversal of 2556561020 is 201656552.

It is a congruent number.

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 31 ways as a sum of consecutive naturals, for example, 3646670 + ... + 3647370.

It is an arithmetic number, because the mean of its divisors is an integer number (61400430).

Almost surely, 2^2556561020 is an apocalyptic number.

2556561020 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 2556561020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2947220640).

2556561020 is an abundant number, since it is smaller than the sum of its proper divisors (3337880260).

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

2556561020 is a wasteful number, since it uses less digits than its factorization.

2556561020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 832 (or 804 counting only the distinct ones).

The product of its (nonzero) digits is 18000, while the sum is 32.

The square root of 2556561020 is about 50562.4467366839. The cubic root of 2556561020 is about 1367.3679231462.

The spelling of 2556561020 in words is "two billion, five hundred fifty-six million, five hundred sixty-one thousand, twenty".