77686979 has 2 divisors, whose sum is σ = 77686980. Its totient is φ = 77686978.

The previous prime is 77686951. The next prime is 77687003. The reversal of 77686979 is 97968677.

It is a strong prime.

It is an emirp because it is prime and its reverse (97968677) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77686979 is a prime.

It is a super-2 number, since 2×77686979² = 12070533412292882, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (77686909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38843489 + 38843490.

It is an arithmetic number, because the mean of its divisors is an integer number (38843490).

Almost surely, 2^77686979 is an apocalyptic number.

77686979 is a deficient number, since it is larger than the sum of its proper divisors (1).

77686979 is an equidigital number, since it uses as much as digits as its factorization.

77686979 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8001504, while the sum is 59.

The square root of 77686979 is about 8814.0217267715. The cubic root of 77686979 is about 426.6935498062.

The spelling of 77686979 in words is "seventy-seven million, six hundred eighty-six thousand, nine hundred seventy-nine".