669506647 has 2 divisors, whose sum is σ = 669506648. Its totient is φ = 669506646.

The previous prime is 669506569. The next prime is 669506693. The reversal of 669506647 is 746605966.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 669506647 - 2¹⁹ = 668982359 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 669506647.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (669506447) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334753323 + 334753324.

It is an arithmetic number, because the mean of its divisors is an integer number (334753324).

Almost surely, 2^669506647 is an apocalyptic number.

669506647 is a deficient number, since it is larger than the sum of its proper divisors (1).

669506647 is an equidigital number, since it uses as much as digits as its factorization.

669506647 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1632960, while the sum is 49.

The square root of 669506647 is about 25874.8265114957. The cubic root of 669506647 is about 874.8191830997.

The spelling of 669506647 in words is "six hundred sixty-nine million, five hundred six thousand, six hundred forty-seven".