665767387 has 4 divisors (see below), whose sum is σ = 677051640. Its totient is φ = 654483136.

The previous prime is 665767367. The next prime is 665767393. The reversal of 665767387 is 783767566.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665767387 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665767367) 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, 5642038 + ... + 5642155.

It is an arithmetic number, because the mean of its divisors is an integer number (169262910).

Almost surely, 2^665767387 is an apocalyptic number.

665767387 is a deficient number, since it is larger than the sum of its proper divisors (11284253).

665767387 is a wasteful number, since it uses less digits than its factorization.

665767387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11284252.

The product of its digits is 8890560, while the sum is 55.

The square root of 665767387 is about 25802.4686222074. The cubic root of 665767387 is about 873.1874914123.

The spelling of 665767387 in words is "six hundred sixty-five million, seven hundred sixty-seven thousand, three hundred eighty-seven".