665330639 has 2 divisors, whose sum is σ = 665330640. Its totient is φ = 665330638.

The previous prime is 665330621. The next prime is 665330689. The reversal of 665330639 is 936033566.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665330639 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 665330596 and 665330605.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665330689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332665319 + 332665320.

It is an arithmetic number, because the mean of its divisors is an integer number (332665320).

Almost surely, 2^665330639 is an apocalyptic number.

665330639 is a deficient number, since it is larger than the sum of its proper divisors (1).

665330639 is an equidigital number, since it uses as much as digits as its factorization.

665330639 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 262440, while the sum is 41.

The square root of 665330639 is about 25794.0039350233. The cubic root of 665330639 is about 872.9965106380.

The spelling of 665330639 in words is "six hundred sixty-five million, three hundred thirty thousand, six hundred thirty-nine".