2556120105 has 64 divisors (see below), whose sum is σ = 5665536000. Its totient is φ = 1062279360.

The previous prime is 2556120101. The next prime is 2556120109. The reversal of 2556120105 is 5010216552.

2556120105 is a `hidden beast` number, since 2 + 556 + 1 + 2 + 0 + 105 = 666.

It is an interprime number because it is at equal distance from previous prime (2556120101) and next prime (2556120109).

It is not a de Polignac number, because 2556120105 - 2² = 2556120101 is a prime.

It is a super-2 number, since 2×2556120105² = 13067499982370422050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (2556120101) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 112555 + ... + 133344.

It is an arithmetic number, because the mean of its divisors is an integer number (88524000).

Almost surely, 2^2556120105 is an apocalyptic number.

It is an amenable number.

2556120105 is an abundant number, since it is smaller than the sum of its proper divisors (3109415895).

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

2556120105 is a wasteful number, since it uses less digits than its factorization.

2556120105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 245931 (or 245925 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 27.

The square root of 2556120105 is about 50558.0864451969. The cubic root of 2556120105 is about 1367.2893113332.

Adding to 2556120105 its reverse (5010216552), we get a palindrome (7566336657).

The spelling of 2556120105 in words is "two billion, five hundred fifty-six million, one hundred twenty thousand, one hundred five".