657671669 has 2 divisors, whose sum is σ = 657671670. Its totient is φ = 657671668.

The previous prime is 657671621. The next prime is 657671687. The reversal of 657671669 is 966176756.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 468939025 + 188732644 = 21655^2 + 13738^2 .

It is a cyclic number.

It is not a de Polignac number, because 657671669 - 2²⁸ = 389236213 is a prime.

It is a super-2 number, since 2×657671669² = 865064048410491122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 657671669.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (657671869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328835834 + 328835835.

It is an arithmetic number, because the mean of its divisors is an integer number (328835835).

Almost surely, 2^657671669 is an apocalyptic number.

It is an amenable number.

657671669 is a deficient number, since it is larger than the sum of its proper divisors (1).

657671669 is an equidigital number, since it uses as much as digits as its factorization.

657671669 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2857680, while the sum is 53.

The square root of 657671669 is about 25645.1100407076. The cubic root of 657671669 is about 869.6337336129.

The spelling of 657671669 in words is "six hundred fifty-seven million, six hundred seventy-one thousand, six hundred sixty-nine".