39999779 has 2 divisors, whose sum is σ = 39999780. Its totient is φ = 39999778.

The previous prime is 39999763. The next prime is 39999781. The reversal of 39999779 is 97799993.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 39999779 - 2⁴ = 39999763 is a prime.

It is a Sophie Germain prime.

Together with 39999781, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (39999709) 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, 19999889 + 19999890.

It is an arithmetic number, because the mean of its divisors is an integer number (19999890).

Almost surely, 2^39999779 is an apocalyptic number.

39999779 is a deficient number, since it is larger than the sum of its proper divisors (1).

39999779 is an equidigital number, since it uses as much as digits as its factorization.

39999779 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8680203, while the sum is 62.

The square root of 39999779 is about 6324.5378487286. The cubic root of 39999779 is about 341.9945594930.

The spelling of 39999779 in words is "thirty-nine million, nine hundred ninety-nine thousand, seven hundred seventy-nine".