665896397 has 4 divisors (see below), whose sum is σ = 666229536. Its totient is φ = 665563260.

The previous prime is 665896393. The next prime is 665896421. The reversal of 665896397 is 793698566.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 793698566 = 2 ⋅396849283.

It is a cyclic number.

It is not a de Polignac number, because 665896397 - 2² = 665896393 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665896393) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 163553 + ... + 167574.

It is an arithmetic number, because the mean of its divisors is an integer number (166557384).

Almost surely, 2^665896397 is an apocalyptic number.

It is an amenable number.

665896397 is a deficient number, since it is larger than the sum of its proper divisors (333139).

665896397 is a wasteful number, since it uses less digits than its factorization.

665896397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333138.

The product of its digits is 14696640, while the sum is 59.

The square root of 665896397 is about 25804.9684557064. The cubic root of 665896397 is about 873.2438888092.

The spelling of 665896397 in words is "six hundred sixty-five million, eight hundred ninety-six thousand, three hundred ninety-seven".