123666779 has 2 divisors, whose sum is σ = 123666780. Its totient is φ = 123666778.

The previous prime is 123666769. The next prime is 123666787. The reversal of 123666779 is 977666321.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-123666779 is a prime.

It is a plaindrome in base 10.

It is not a weakly prime, because it can be changed into another prime (123666769) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61833389 + 61833390.

It is an arithmetic number, because the mean of its divisors is an integer number (61833390).

Almost surely, 2^123666779 is an apocalyptic number.

123666779 is a deficient number, since it is larger than the sum of its proper divisors (1).

123666779 is an equidigital number, since it uses as much as digits as its factorization.

123666779 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 571536, while the sum is 47.

The square root of 123666779 is about 11120.5565957824. The cubic root of 123666779 is about 498.2160143608.

The spelling of 123666779 in words is "one hundred twenty-three million, six hundred sixty-six thousand, seven hundred seventy-nine".