665676091 has 2 divisors, whose sum is σ = 665676092. Its totient is φ = 665676090.

The previous prime is 665676079. The next prime is 665676169. The reversal of 665676091 is 190676566.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 665676091 - 2⁵ = 665676059 is a prime.

It is not a weakly prime, because it can be changed into another prime (665676071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332838045 + 332838046.

It is an arithmetic number, because the mean of its divisors is an integer number (332838046).

Almost surely, 2^665676091 is an apocalyptic number.

665676091 is a deficient number, since it is larger than the sum of its proper divisors (1).

665676091 is an equidigital number, since it uses as much as digits as its factorization.

665676091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 408240, while the sum is 46.

The square root of 665676091 is about 25800.6994285039. The cubic root of 665676091 is about 873.1475764855.

The spelling of 665676091 in words is "six hundred sixty-five million, six hundred seventy-six thousand, ninety-one".