823509837979 has 4 divisors (see below), whose sum is σ = 823573693800. Its totient is φ = 823445982160.

The previous prime is 823509837977. The next prime is 823509838031. The reversal of 823509837979 is 979738905328.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 823509837979 - 2¹ = 823509837977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (823509837977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31908562 + ... + 31934359.

It is an arithmetic number, because the mean of its divisors is an integer number (205893423450).

Almost surely, 2^823509837979 is an apocalyptic number.

823509837979 is a deficient number, since it is larger than the sum of its proper divisors (63855821).

823509837979 is a wasteful number, since it uses less digits than its factorization.

823509837979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63855820.

The product of its (nonzero) digits is 205752960, while the sum is 70.

The spelling of 823509837979 in words is "eight hundred twenty-three billion, five hundred nine million, eight hundred thirty-seven thousand, nine hundred seventy-nine".