999809479 has 2 divisors, whose sum is σ = 999809480. Its totient is φ = 999809478.

The previous prime is 999809453. The next prime is 999809497. The reversal of 999809479 is 974908999.

Together with next prime (999809497) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is an emirp because it is prime and its reverse (974908999) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 999809479 - 2⁷ = 999809351 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 999809479.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999809779) 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, 499904739 + 499904740.

It is an arithmetic number, because the mean of its divisors is an integer number (499904740).

Almost surely, 2^999809479 is an apocalyptic number.

999809479 is a deficient number, since it is larger than the sum of its proper divisors (1).

999809479 is an equidigital number, since it uses as much as digits as its factorization.

999809479 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13226976, while the sum is 64.

The square root of 999809479 is about 31619.7640566782. The cubic root of 999809479 is about 999.9364889664.

The spelling of 999809479 in words is "nine hundred ninety-nine million, eight hundred nine thousand, four hundred seventy-nine".