66776407 has 2 divisors, whose sum is σ = 66776408. Its totient is φ = 66776406.

The previous prime is 66776401. The next prime is 66776417. The reversal of 66776407 is 70467766.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66776407 - 2³ = 66776399 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66776401) 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, 33388203 + 33388204.

It is an arithmetic number, because the mean of its divisors is an integer number (33388204).

Almost surely, 2^66776407 is an apocalyptic number.

66776407 is a deficient number, since it is larger than the sum of its proper divisors (1).

66776407 is an equidigital number, since it uses as much as digits as its factorization.

66776407 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 296352, while the sum is 43.

The square root of 66776407 is about 8171.6832415360. The cubic root of 66776407 is about 405.7024986952.

The spelling of 66776407 in words is "sixty-six million, seven hundred seventy-six thousand, four hundred seven".