668777 has 4 divisors (see below), whose sum is σ = 672000. Its totient is φ = 665556.

The previous prime is 668761. The next prime is 668791. The reversal of 668777 is 777866.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 777866 = 2 ⋅388933.

It is a cyclic number.

It is not a de Polignac number, because 668777 - 2⁴ = 668761 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (668737) 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, 1277 + ... + 1722.

It is an arithmetic number, because the mean of its divisors is an integer number (168000).

2⁶⁶⁸⁷⁷⁷ is an apocalyptic number.

It is an amenable number.

668777 is a deficient number, since it is larger than the sum of its proper divisors (3223).

668777 is a wasteful number, since it uses less digits than its factorization.

668777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3222.

The product of its digits is 98784, while the sum is 41.

The square root of 668777 is about 817.7878698049. The cubic root of 668777 is about 87.4501266806.

The spelling of 668777 in words is "six hundred sixty-eight thousand, seven hundred seventy-seven".