3666333581 has 2 divisors, whose sum is σ = 3666333582. Its totient is φ = 3666333580.

The previous prime is 3666333563. The next prime is 3666333623. The reversal of 3666333581 is 1853336663.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3662065225 + 4268356 = 60515^2 + 2066^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3666333581 is a prime.

It is a super-2 number, since 2×3666333581² = 26884003854336567122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3666335581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1833166790 + 1833166791.

It is an arithmetic number, because the mean of its divisors is an integer number (1833166791).

Almost surely, 2^3666333581 is an apocalyptic number.

It is an amenable number.

3666333581 is a deficient number, since it is larger than the sum of its proper divisors (1).

3666333581 is an equidigital number, since it uses as much as digits as its factorization.

3666333581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 699840, while the sum is 44.

The square root of 3666333581 is about 60550.2566551125. The cubic root of 3666333581 is about 1541.9749751031.

The spelling of 3666333581 in words is "three billion, six hundred sixty-six million, three hundred thirty-three thousand, five hundred eighty-one".