66839873 has 2 divisors, whose sum is σ = 66839874. Its totient is φ = 66839872.

The previous prime is 66839849. The next prime is 66839917. The reversal of 66839873 is 37893866.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65011969 + 1827904 = 8063^2 + 1352^2 .

It is a cyclic number.

It is not a de Polignac number, because 66839873 - 2¹² = 66835777 is a prime.

It is a super-2 number, since 2×66839873² = 8935137245312258, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66839573) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33419936 + 33419937.

It is an arithmetic number, because the mean of its divisors is an integer number (33419937).

Almost surely, 2^66839873 is an apocalyptic number.

It is an amenable number.

66839873 is a deficient number, since it is larger than the sum of its proper divisors (1).

66839873 is an equidigital number, since it uses as much as digits as its factorization.

66839873 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1306368, while the sum is 50.

The square root of 66839873 is about 8175.5656073449. The cubic root of 66839873 is about 405.8309879973.

The spelling of 66839873 in words is "sixty-six million, eight hundred thirty-nine thousand, eight hundred seventy-three".