665470028161 has 4 divisors (see below), whose sum is σ = 665514181332. Its totient is φ = 665425874992.

The previous prime is 665470028123. The next prime is 665470028191. The reversal of 665470028161 is 161820074566.

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

It can be written as a sum of positive squares in 2 ways, for example, as 43871815936 + 621598212225 = 209456^2 + 788415^2 .

It is a cyclic number.

It is not a de Polignac number, because 665470028161 - 2²³ = 665461639553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665470028191) 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, 22053970 + ... + 22084123.

It is an arithmetic number, because the mean of its divisors is an integer number (166378545333).

Almost surely, 2^665470028161 is an apocalyptic number.

It is an amenable number.

665470028161 is a deficient number, since it is larger than the sum of its proper divisors (44153171).

665470028161 is a wasteful number, since it uses less digits than its factorization.

665470028161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44153170.

The product of its (nonzero) digits is 483840, while the sum is 46.

The spelling of 665470028161 in words is "six hundred sixty-five billion, four hundred seventy million, twenty-eight thousand, one hundred sixty-one".