2556635281 has 2 divisors, whose sum is σ = 2556635282. Its totient is φ = 2556635280.

The previous prime is 2556635267. The next prime is 2556635293. The reversal of 2556635281 is 1825366552.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1939609681 + 617025600 = 44041^2 + 24840^2 .

It is a cyclic number.

It is not a de Polignac number, because 2556635281 - 2¹³ = 2556627089 is a prime.

It is a super-2 number, since 2×2556635281² = 13072767920107897922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (2556635261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1278317640 + 1278317641.

It is an arithmetic number, because the mean of its divisors is an integer number (1278317641).

Almost surely, 2^2556635281 is an apocalyptic number.

It is an amenable number.

2556635281 is a deficient number, since it is larger than the sum of its proper divisors (1).

2556635281 is an equidigital number, since it uses as much as digits as its factorization.

2556635281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 432000, while the sum is 43.

The square root of 2556635281 is about 50563.1810807034. The cubic root of 2556635281 is about 1367.3811624320.

The spelling of 2556635281 in words is "two billion, five hundred fifty-six million, six hundred thirty-five thousand, two hundred eighty-one".