66776623 has 2 divisors, whose sum is σ = 66776624. Its totient is φ = 66776622.

The previous prime is 66776617. The next prime is 66776669. The reversal of 66776623 is 32667766.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66776623 - 2²¹ = 64679471 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66776623.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66776603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33388311 + 33388312.

It is an arithmetic number, because the mean of its divisors is an integer number (33388312).

Almost surely, 2^66776623 is an apocalyptic number.

66776623 is a deficient number, since it is larger than the sum of its proper divisors (1).

66776623 is an equidigital number, since it uses as much as digits as its factorization.

66776623 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 381024, while the sum is 43.

The square root of 66776623 is about 8171.6964578966. The cubic root of 66776623 is about 405.7029361334.

The spelling of 66776623 in words is "sixty-six million, seven hundred seventy-six thousand, six hundred twenty-three".