665499389 has 2 divisors, whose sum is σ = 665499390. Its totient is φ = 665499388.

The previous prime is 665499383. The next prime is 665499421. The reversal of 665499389 is 983994566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 656896900 + 8602489 = 25630^2 + 2933^2 .

It is a cyclic number.

It is not a de Polignac number, because 665499389 - 2¹² = 665495293 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665499383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332749694 + 332749695.

It is an arithmetic number, because the mean of its divisors is an integer number (332749695).

Almost surely, 2^665499389 is an apocalyptic number.

It is an amenable number.

665499389 is a deficient number, since it is larger than the sum of its proper divisors (1).

665499389 is an equidigital number, since it uses as much as digits as its factorization.

665499389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12597120, while the sum is 59.

The square root of 665499389 is about 25797.2748366954. The cubic root of 665499389 is about 873.0703113918.

The spelling of 665499389 in words is "six hundred sixty-five million, four hundred ninety-nine thousand, three hundred eighty-nine".