669319081 has 2 divisors, whose sum is σ = 669319082. Its totient is φ = 669319080.

The previous prime is 669319051. The next prime is 669319153. The reversal of 669319081 is 180913966.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 579846400 + 89472681 = 24080^2 + 9459^2 .

It is a cyclic number.

It is not a de Polignac number, because 669319081 - 2⁷ = 669318953 is a prime.

It is a super-2 number, since 2×669319081² = 895976064381369122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (669319051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334659540 + 334659541.

It is an arithmetic number, because the mean of its divisors is an integer number (334659541).

Almost surely, 2^669319081 is an apocalyptic number.

It is an amenable number.

669319081 is a deficient number, since it is larger than the sum of its proper divisors (1).

669319081 is an equidigital number, since it uses as much as digits as its factorization.

669319081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 69984, while the sum is 43.

The square root of 669319081 is about 25871.2017695352. The cubic root of 669319081 is about 874.7374803209.

The spelling of 669319081 in words is "six hundred sixty-nine million, three hundred nineteen thousand, eighty-one".