66931673 has 2 divisors, whose sum is σ = 66931674. Its totient is φ = 66931672.

The previous prime is 66931643. The next prime is 66931687. The reversal of 66931673 is 37613966.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61418569 + 5513104 = 7837^2 + 2348^2 .

It is a cyclic number.

It is not a de Polignac number, because 66931673 - 2²⁴ = 50154457 is a prime.

It is a Sophie Germain 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 66931673.

It is not a weakly prime, because it can be changed into another prime (66931643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33465836 + 33465837.

It is an arithmetic number, because the mean of its divisors is an integer number (33465837).

Almost surely, 2^66931673 is an apocalyptic number.

It is an amenable number.

66931673 is a deficient number, since it is larger than the sum of its proper divisors (1).

66931673 is an equidigital number, since it uses as much as digits as its factorization.

66931673 is an evil number, because the sum of its binary digits is even.

The product of its digits is 122472, while the sum is 41.

The square root of 66931673 is about 8181.1779714171. The cubic root of 66931673 is about 406.0166967176.

The spelling of 66931673 in words is "sixty-six million, nine hundred thirty-one thousand, six hundred seventy-three".