665777776 has 20 divisors (see below), whose sum is σ = 1292545000. Its totient is φ = 332217792.

The previous prime is 665777773. The next prime is 665777789. The reversal of 665777776 is 677777566.

It is a self number, because there is not a number n which added to its sum of digits gives 665777776.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665777773) 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, 33711 + ... + 49678.

It is an arithmetic number, because the mean of its divisors is an integer number (64627250).

Almost surely, 2^665777776 is an apocalyptic number.

It is an amenable number.

665777776 is a deficient number, since it is larger than the sum of its proper divisors (626767224).

665777776 is a wasteful number, since it uses less digits than its factorization.

665777776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83896 (or 83890 counting only the distinct ones).

The product of its digits is 18151560, while the sum is 58.

The square root of 665777776 is about 25802.6699393687. The cubic root of 665777776 is about 873.1920332877.

The spelling of 665777776 in words is "six hundred sixty-five million, seven hundred seventy-seven thousand, seven hundred seventy-six".