6664345081 has 2 divisors, whose sum is σ = 6664345082. Its totient is φ = 6664345080.

The previous prime is 6664345043. The next prime is 6664345097. The reversal of 6664345081 is 1805434666.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5320389481 + 1343955600 = 72941^2 + 36660^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6664345081 is a prime.

It is a super-2 number, since 2×6664345081² = 88826990717297793122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (6664345031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3332172540 + 3332172541.

It is an arithmetic number, because the mean of its divisors is an integer number (3332172541).

Almost surely, 2^6664345081 is an apocalyptic number.

It is an amenable number.

6664345081 is a deficient number, since it is larger than the sum of its proper divisors (1).

6664345081 is an equidigital number, since it uses as much as digits as its factorization.

6664345081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 414720, while the sum is 43.

The square root of 6664345081 is about 81635.4401041606. The cubic root of 6664345081 is about 1881.8535628217.

The spelling of 6664345081 in words is "six billion, six hundred sixty-four million, three hundred forty-five thousand, eighty-one".