665679653 has 2 divisors, whose sum is σ = 665679654. Its totient is φ = 665679652.

The previous prime is 665679643. The next prime is 665679739. The reversal of 665679653 is 356976566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 387223684 + 278455969 = 19678^2 + 16687^2 .

It is a cyclic number.

It is not a de Polignac number, because 665679653 - 2²⁶ = 598570789 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 665679595 and 665679604.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665679643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332839826 + 332839827.

It is an arithmetic number, because the mean of its divisors is an integer number (332839827).

Almost surely, 2^665679653 is an apocalyptic number.

It is an amenable number.

665679653 is a deficient number, since it is larger than the sum of its proper divisors (1).

665679653 is an equidigital number, since it uses as much as digits as its factorization.

665679653 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6123600, while the sum is 53.

The square root of 665679653 is about 25800.7684575479. The cubic root of 665679653 is about 873.1491338727.

The spelling of 665679653 in words is "six hundred sixty-five million, six hundred seventy-nine thousand, six hundred fifty-three".