665232778027 has 4 divisors (see below), whose sum is σ = 683212042336. Its totient is φ = 647253513720.

The previous prime is 665232778009. The next prime is 665232778039. The reversal of 665232778027 is 720877232566.

It is a happy number.

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 665232778027 - 2²³ = 665224389419 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665232778057) 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, 8989632099 + ... + 8989632172.

It is an arithmetic number, because the mean of its divisors is an integer number (170803010584).

Almost surely, 2^665232778027 is an apocalyptic number.

665232778027 is a deficient number, since it is larger than the sum of its proper divisors (17979264309).

665232778027 is a wasteful number, since it uses less digits than its factorization.

665232778027 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17979264308.

The product of its (nonzero) digits is 11854080, while the sum is 55.

The spelling of 665232778027 in words is "six hundred sixty-five billion, two hundred thirty-two million, seven hundred seventy-eight thousand, twenty-seven".