79666669 has 2 divisors, whose sum is σ = 79666670. Its totient is φ = 79666668.

The previous prime is 79666597. The next prime is 79666703. The reversal of 79666669 is 96666697.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 66634569 + 13032100 = 8163^2 + 3610^2 .

It is a cyclic number.

It is not a de Polignac number, because 79666669 - 2¹³ = 79658477 is a prime.

It is a super-2 number, since 2×79666669² = 12693556299111122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79606669) 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, 39833334 + 39833335.

It is an arithmetic number, because the mean of its divisors is an integer number (39833335).

Almost surely, 2^79666669 is an apocalyptic number.

It is an amenable number.

79666669 is a deficient number, since it is larger than the sum of its proper divisors (1).

79666669 is an equidigital number, since it uses as much as digits as its factorization.

79666669 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4408992, while the sum is 55.

The square root of 79666669 is about 8925.6186900405. The cubic root of 79666669 is about 430.2876550110.

The spelling of 79666669 in words is "seventy-nine million, six hundred sixty-six thousand, six hundred sixty-nine".