66699223 has 2 divisors, whose sum is σ = 66699224. Its totient is φ = 66699222.

The previous prime is 66699209. The next prime is 66699229. The reversal of 66699223 is 32299666.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66699223 - 2⁹ = 66698711 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66699223.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66699229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33349611 + 33349612.

It is an arithmetic number, because the mean of its divisors is an integer number (33349612).

Almost surely, 2^66699223 is an apocalyptic number.

66699223 is a deficient number, since it is larger than the sum of its proper divisors (1).

66699223 is an equidigital number, since it uses as much as digits as its factorization.

66699223 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 209952, while the sum is 43.

The square root of 66699223 is about 8166.9592260523. The cubic root of 66699223 is about 405.5461270286.

The spelling of 66699223 in words is "sixty-six million, six hundred ninety-nine thousand, two hundred twenty-three".