66806947 has 2 divisors, whose sum is σ = 66806948. Its totient is φ = 66806946.

The previous prime is 66806921. The next prime is 66806969. The reversal of 66806947 is 74960866.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66806947 - 2⁷ = 66806819 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66806897 and 66806906.

It is not a weakly prime, because it can be changed into another prime (66806347) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33403473 + 33403474.

It is an arithmetic number, because the mean of its divisors is an integer number (33403474).

Almost surely, 2^66806947 is an apocalyptic number.

66806947 is a deficient number, since it is larger than the sum of its proper divisors (1).

66806947 is an equidigital number, since it uses as much as digits as its factorization.

66806947 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 435456, while the sum is 46.

The square root of 66806947 is about 8173.5516759852. The cubic root of 66806947 is about 405.7643382305.

The spelling of 66806947 in words is "sixty-six million, eight hundred six thousand, nine hundred forty-seven".