66756947 has 2 divisors, whose sum is σ = 66756948. Its totient is φ = 66756946.

The previous prime is 66756913. The next prime is 66756961. The reversal of 66756947 is 74965766.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66756947 - 2²⁰ = 65708371 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66756895 and 66756904.

It is not a weakly prime, because it can be changed into another prime (66756047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33378473 + 33378474.

It is an arithmetic number, because the mean of its divisors is an integer number (33378474).

Almost surely, 2^66756947 is an apocalyptic number.

66756947 is a deficient number, since it is larger than the sum of its proper divisors (1).

66756947 is an equidigital number, since it uses as much as digits as its factorization.

66756947 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1905120, while the sum is 50.

The square root of 66756947 is about 8170.4924576185. The cubic root of 66756947 is about 405.6630848861.

The spelling of 66756947 in words is "sixty-six million, seven hundred fifty-six thousand, nine hundred forty-seven".