999957779 has 2 divisors, whose sum is σ = 999957780. Its totient is φ = 999957778.

The previous prime is 999957773. The next prime is 999957841. The reversal of 999957779 is 977759999.

999957779 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is an emirp because it is prime and its reverse (977759999) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-999957779 is a prime.

It is a super-2 number, since 2×999957779² = 1999831119565225682, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (999957773) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499978889 + 499978890.

It is an arithmetic number, because the mean of its divisors is an integer number (499978890).

Almost surely, 2^999957779 is an apocalyptic number.

999957779 is a deficient number, since it is larger than the sum of its proper divisors (1).

999957779 is an equidigital number, since it uses as much as digits as its factorization.

999957779 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 101269035, while the sum is 71.

The square root of 999957779 is about 31622.1090220118. The cubic root of 999957779 is about 999.9859261353.

The spelling of 999957779 in words is "nine hundred ninety-nine million, nine hundred fifty-seven thousand, seven hundred seventy-nine".