665604220544611 has 4 divisors (see below), whose sum is σ = 665614076888824. Its totient is φ = 665594364200400.

The previous prime is 665604220544609. The next prime is 665604220544663. The reversal of 665604220544611 is 116445022406566.

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 665604220544611 - 2¹ = 665604220544609 is a prime.

It is a super-2 number, since 2×665604220544611² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665604220545611) 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, 4928070810 + ... + 4928205871.

It is an arithmetic number, because the mean of its divisors is an integer number (166403519222206).

Almost surely, 2^{665604220544611} is an apocalyptic number.

665604220544611 is a deficient number, since it is larger than the sum of its proper divisors (9856344213).

665604220544611 is an equidigital number, since it uses as much as digits as its factorization.

665604220544611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9856344212.

The product of its (nonzero) digits is 8294400, while the sum is 52.

The spelling of 665604220544611 in words is "six hundred sixty-five trillion, six hundred four billion, two hundred twenty million, five hundred forty-four thousand, six hundred eleven".