665465623 has 4 divisors (see below), whose sum is σ = 686932288. Its totient is φ = 643998960.

The previous prime is 665465617. The next prime is 665465627. The reversal of 665465623 is 326564566.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 665465623 - 2²⁵ = 631911191 is a prime.

It is a super-4 number, since 4×665465623⁴ (a number of 36 digits) contains 4444 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 665465623.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665465627) 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, 10733286 + ... + 10733347.

It is an arithmetic number, because the mean of its divisors is an integer number (171733072).

Almost surely, 2^665465623 is an apocalyptic number.

665465623 is a deficient number, since it is larger than the sum of its proper divisors (21466665).

665465623 is a wasteful number, since it uses less digits than its factorization.

665465623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21466664.

The product of its digits is 777600, while the sum is 43.

The square root of 665465623 is about 25796.6203794218. The cubic root of 665465623 is about 873.0555452421.

The spelling of 665465623 in words is "six hundred sixty-five million, four hundred sixty-five thousand, six hundred twenty-three".