660115665623 has 4 divisors (see below), whose sum is σ = 669158346048. Its totient is φ = 651072985200.

The previous prime is 660115665619. The next prime is 660115665631. The reversal of 660115665623 is 326566511066.

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

It is a cyclic number.

It is not a de Polignac number, because 660115665623 - 2² = 660115665619 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 (660115665613) 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, 4521340103 + ... + 4521340248.

It is an arithmetic number, because the mean of its divisors is an integer number (167289586512).

Almost surely, 2^660115665623 is an apocalyptic number.

660115665623 is a deficient number, since it is larger than the sum of its proper divisors (9042680425).

660115665623 is an equidigital number, since it uses as much as digits as its factorization.

660115665623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9042680424.

The product of its (nonzero) digits is 1166400, while the sum is 47.

The spelling of 660115665623 in words is "six hundred sixty billion, one hundred fifteen million, six hundred sixty-five thousand, six hundred twenty-three".