669404077 has 4 divisors (see below), whose sum is σ = 671199100. Its totient is φ = 667609056.

The previous prime is 669404059. The next prime is 669404149. The reversal of 669404077 is 770404966.

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 352350441 + 317053636 = 18771^2 + 17806^2 .

It is a cyclic number.

It is not a de Polignac number, because 669404077 - 2²⁷ = 535186349 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669404027) 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, 896952 + ... + 897697.

It is an arithmetic number, because the mean of its divisors is an integer number (167799775).

Almost surely, 2^669404077 is an apocalyptic number.

It is an amenable number.

669404077 is a deficient number, since it is larger than the sum of its proper divisors (1795023).

669404077 is a wasteful number, since it uses less digits than its factorization.

669404077 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1795022.

The product of its (nonzero) digits is 254016, while the sum is 43.

The square root of 669404077 is about 25872.8443933016. The cubic root of 669404077 is about 874.7745060296.

It can be divided in two parts, 66940 and 4077, that added together give a palindrome (71017).

The spelling of 669404077 in words is "six hundred sixty-nine million, four hundred four thousand, seventy-seven".