66913897 has 2 divisors, whose sum is σ = 66913898. Its totient is φ = 66913896.

The previous prime is 66913867. The next prime is 66913909. The reversal of 66913897 is 79831966.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65464281 + 1449616 = 8091^2 + 1204^2 .

It is a cyclic number.

It is not a de Polignac number, because 66913897 - 2²³ = 58525289 is a prime.

It is a super-2 number, since 2×66913897² = 8954939223453218, 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 66913897.

It is not a weakly prime, because it can be changed into another prime (66913867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33456948 + 33456949.

It is an arithmetic number, because the mean of its divisors is an integer number (33456949).

Almost surely, 2^66913897 is an apocalyptic number.

It is an amenable number.

66913897 is a deficient number, since it is larger than the sum of its proper divisors (1).

66913897 is an equidigital number, since it uses as much as digits as its factorization.

66913897 is an odious number, because the sum of its binary digits is odd.

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

The square root of 66913897 is about 8180.0915031557. The cubic root of 66913897 is about 405.9807496515.

The spelling of 66913897 in words is "sixty-six million, nine hundred thirteen thousand, eight hundred ninety-seven".