669688897 has 2 divisors, whose sum is σ = 669688898. Its totient is φ = 669688896.

The previous prime is 669688843. The next prime is 669688951. The reversal of 669688897 is 798886966.

It is a balanced prime because it is at equal distance from previous prime (669688843) and next prime (669688951).

It can be written as a sum of positive squares in only one way, i.e., 544942336 + 124746561 = 23344^2 + 11169^2 .

It is a cyclic number.

It is not a de Polignac number, because 669688897 - 2¹⁹ = 669164609 is a prime.

It is not a weakly prime, because it can be changed into another prime (669683897) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334844448 + 334844449.

It is an arithmetic number, because the mean of its divisors is an integer number (334844449).

Almost surely, 2^669688897 is an apocalyptic number.

It is an amenable number.

669688897 is a deficient number, since it is larger than the sum of its proper divisors (1).

669688897 is an equidigital number, since it uses as much as digits as its factorization.

669688897 is an evil number, because the sum of its binary digits is even.

The product of its digits is 62705664, while the sum is 67.

The square root of 669688897 is about 25878.3480346022. The cubic root of 669688897 is about 874.8985556407.

The spelling of 669688897 in words is "six hundred sixty-nine million, six hundred eighty-eight thousand, eight hundred ninety-seven".