665609319 has 12 divisors (see below), whose sum is σ = 997044776. Its totient is φ = 443739384.

The previous prime is 665609257. The next prime is 665609327. The reversal of 665609319 is 913906566.

665609319 is a `hidden beast` number, since 6 + 6 + 5 + 609 + 31 + 9 = 666.

It is not a de Polignac number, because 665609319 - 2¹⁶ = 665543783 is a prime.

It is a super-2 number, since 2×665609319² = 886071531079287522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665609389) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1369324 + ... + 1369809.

Almost surely, 2^665609319 is an apocalyptic number.

665609319 is a deficient number, since it is larger than the sum of its proper divisors (331435457).

665609319 is an equidigital number, since it uses as much as digits as its factorization.

665609319 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2739148 (or 2739136 counting only the distinct ones).

The product of its (nonzero) digits is 262440, while the sum is 45.

The square root of 665609319 is about 25799.4054001250. The cubic root of 665609319 is about 873.1183812257.

The spelling of 665609319 in words is "six hundred sixty-five million, six hundred nine thousand, three hundred nineteen".