3556556581 has 2 divisors, whose sum is σ = 3556556582. Its totient is φ = 3556556580.

The previous prime is 3556556533. The next prime is 3556556593. The reversal of 3556556581 is 1856556553.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3244327681 + 312228900 = 56959^2 + 17670^2 .

It is a cyclic number.

It is not a de Polignac number, because 3556556581 - 2¹³ = 3556548389 is a prime.

It is a super-2 number, since 2×3556556581² = 25298189427708819122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3556556981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1778278290 + 1778278291.

It is an arithmetic number, because the mean of its divisors is an integer number (1778278291).

Almost surely, 2^3556556581 is an apocalyptic number.

It is an amenable number.

3556556581 is a deficient number, since it is larger than the sum of its proper divisors (1).

3556556581 is an equidigital number, since it uses as much as digits as its factorization.

3556556581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2700000, while the sum is 49.

The square root of 3556556581 is about 59636.8726628082. The cubic root of 3556556581 is about 1526.4288793082.

The spelling of 3556556581 in words is "three billion, five hundred fifty-six million, five hundred fifty-six thousand, five hundred eighty-one".