665115013261 has 8 divisors (see below), whose sum is σ = 671719972248. Its totient is φ = 658510440000.

The previous prime is 665115013259. The next prime is 665115013309. The reversal of 665115013261 is 162310511566.

It can be written as a sum of positive squares in 4 ways, for example, as 93624372361 + 571490640900 = 305981^2 + 755970^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 665115013261 - 2¹ = 665115013259 is a prime.

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 665115013261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665115013561) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4408291 + ... + 4556671.

It is an arithmetic number, because the mean of its divisors is an integer number (83964996531).

Almost surely, 2^665115013261 is an apocalyptic number.

It is an amenable number.

665115013261 is a deficient number, since it is larger than the sum of its proper divisors (6604958987).

665115013261 is a wasteful number, since it uses less digits than its factorization.

665115013261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192863.

The product of its (nonzero) digits is 32400, while the sum is 37.

The spelling of 665115013261 in words is "six hundred sixty-five billion, one hundred fifteen million, thirteen thousand, two hundred sixty-one".