669911647 has 2 divisors, whose sum is σ = 669911648. Its totient is φ = 669911646.

The previous prime is 669911611. The next prime is 669911659. The reversal of 669911647 is 746119966.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 669911647 - 2²³ = 661523039 is a prime.

It is a super-2 number, since 2×669911647² = 897563229572505218, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 669911647.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (669921647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334955823 + 334955824.

It is an arithmetic number, because the mean of its divisors is an integer number (334955824).

Almost surely, 2^669911647 is an apocalyptic number.

669911647 is a deficient number, since it is larger than the sum of its proper divisors (1).

669911647 is an equidigital number, since it uses as much as digits as its factorization.

669911647 is an evil number, because the sum of its binary digits is even.

The product of its digits is 489888, while the sum is 49.

The square root of 669911647 is about 25882.6514677303. The cubic root of 669911647 is about 874.9955469705.

The spelling of 669911647 in words is "six hundred sixty-nine million, nine hundred eleven thousand, six hundred forty-seven".