66797779 has 2 divisors, whose sum is σ = 66797780. Its totient is φ = 66797778.

The previous prime is 66797771. The next prime is 66797821. The reversal of 66797779 is 97779766.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66797779 - 2³ = 66797771 is a prime.

It is not a weakly prime, because it can be changed into another prime (66797771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33398889 + 33398890.

It is an arithmetic number, because the mean of its divisors is an integer number (33398890).

Almost surely, 2^66797779 is an apocalyptic number.

66797779 is a deficient number, since it is larger than the sum of its proper divisors (1).

66797779 is an equidigital number, since it uses as much as digits as its factorization.

66797779 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7001316, while the sum is 58.

The square root of 66797779 is about 8172.9908234379. The cubic root of 66797779 is about 405.7457762006.

It can be divided in two parts, 66797 and 779, that added together give a palindrome (67576).

The spelling of 66797779 in words is "sixty-six million, seven hundred ninety-seven thousand, seven hundred seventy-nine".