66217447 has 2 divisors, whose sum is σ = 66217448. Its totient is φ = 66217446.

The previous prime is 66217429. The next prime is 66217453. The reversal of 66217447 is 74471266.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66217447 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66217427) 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, 33108723 + 33108724.

It is an arithmetic number, because the mean of its divisors is an integer number (33108724).

Almost surely, 2^66217447 is an apocalyptic number.

66217447 is a deficient number, since it is larger than the sum of its proper divisors (1).

66217447 is an equidigital number, since it uses as much as digits as its factorization.

66217447 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 56448, while the sum is 37.

The square root of 66217447 is about 8137.4103374477. The cubic root of 66217447 is about 404.5673314647.

The spelling of 66217447 in words is "sixty-six million, two hundred seventeen thousand, four hundred forty-seven".