66996947 has 2 divisors, whose sum is σ = 66996948. Its totient is φ = 66996946.

The previous prime is 66996889. The next prime is 66996961. The reversal of 66996947 is 74969966.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66996947 - 2¹⁰ = 66995923 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66996892 and 66996901.

It is not a weakly prime, because it can be changed into another prime (66996997) 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, 33498473 + 33498474.

It is an arithmetic number, because the mean of its divisors is an integer number (33498474).

Almost surely, 2^66996947 is an apocalyptic number.

66996947 is a deficient number, since it is larger than the sum of its proper divisors (1).

66996947 is an equidigital number, since it uses as much as digits as its factorization.

66996947 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4408992, while the sum is 56.

The square root of 66996947 is about 8185.1662780911. The cubic root of 66996947 is about 406.1486408432.

The spelling of 66996947 in words is "sixty-six million, nine hundred ninety-six thousand, nine hundred forty-seven".