3666968581 has 2 divisors, whose sum is σ = 3666968582. Its totient is φ = 3666968580.

The previous prime is 3666968551. The next prime is 3666968639. The reversal of 3666968581 is 1858696663.

It is an a-pointer prime, because the next prime (3666968639) can be obtained adding 3666968581 to its sum of digits (58).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1941812356 + 1725156225 = 44066^2 + 41535^2 .

It is a cyclic number.

It is not a de Polignac number, because 3666968581 - 2⁵ = 3666968549 is a prime.

It is a super-2 number, since 2×3666968581² = 26893317148082307122, which contains 22 as substring.

It is the 60556-th Hogben number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3666968521) by changing a digit.

It is a nontrivial repunit in base 60555.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1833484290 + 1833484291.

It is an arithmetic number, because the mean of its divisors is an integer number (1833484291).

Almost surely, 2^3666968581 is an apocalyptic number.

It is an amenable number.

3666968581 is a deficient number, since it is larger than the sum of its proper divisors (1).

3666968581 is an equidigital number, since it uses as much as digits as its factorization.

3666968581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11197440, while the sum is 58.

The square root of 3666968581 is about 60555.5000061927. The cubic root of 3666968581 is about 1542.0639920609.

The spelling of 3666968581 in words is "three billion, six hundred sixty-six million, nine hundred sixty-eight thousand, five hundred eighty-one".