669745777 has 4 divisors (see below), whose sum is σ = 670179700. Its totient is φ = 669311856.

The previous prime is 669745771. The next prime is 669745859. The reversal of 669745777 is 777547966.

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

It can be written as a sum of positive squares in 2 ways, for example, as 359140401 + 310605376 = 18951^2 + 17624^2 .

It is a cyclic number.

It is not a de Polignac number, because 669745777 - 2¹¹ = 669743729 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (669745771) 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, 214638 + ... + 217735.

It is an arithmetic number, because the mean of its divisors is an integer number (167544925).

Almost surely, 2^669745777 is an apocalyptic number.

It is an amenable number.

669745777 is a deficient number, since it is larger than the sum of its proper divisors (433923).

669745777 is a wasteful number, since it uses less digits than its factorization.

669745777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433922.

The product of its digits is 15558480, while the sum is 58.

The square root of 669745777 is about 25879.4469995014. The cubic root of 669745777 is about 874.9233247642.

The spelling of 669745777 in words is "six hundred sixty-nine million, seven hundred forty-five thousand, seven hundred seventy-seven".