665052638709 has 4 divisors (see below), whose sum is σ = 886736851616. Its totient is φ = 443368425804.

The previous prime is 665052638707. The next prime is 665052638711. The reversal of 665052638709 is 907836250566.

It is a happy number.

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.

It is an interprime number because it is at equal distance from previous prime (665052638707) and next prime (665052638711).

It is not a de Polignac number, because 665052638709 - 2¹ = 665052638707 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 (665052638707) 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, 110842106449 + ... + 110842106454.

It is an arithmetic number, because the mean of its divisors is an integer number (221684212904).

Almost surely, 2^665052638709 is an apocalyptic number.

It is an amenable number.

665052638709 is a deficient number, since it is larger than the sum of its proper divisors (221684212907).

665052638709 is a wasteful number, since it uses less digits than its factorization.

665052638709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221684212906.

The product of its (nonzero) digits is 16329600, while the sum is 57.

The spelling of 665052638709 in words is "six hundred sixty-five billion, fifty-two million, six hundred thirty-eight thousand, seven hundred nine".