823809931 has 16 divisors (see below), whose sum is σ = 979107840. Its totient is φ = 678172320.

The previous prime is 823809913. The next prime is 823809971. The reversal of 823809931 is 139908328.

It is a happy number.

823809931 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 823809931 - 2⁷ = 823809803 is a prime.

It is a super-3 number, since 3×823809931³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (823809971) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28150 + ... + 49396.

It is an arithmetic number, because the mean of its divisors is an integer number (61194240).

Almost surely, 2^823809931 is an apocalyptic number.

823809931 is a deficient number, since it is larger than the sum of its proper divisors (155297909).

823809931 is a wasteful number, since it uses less digits than its factorization.

823809931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21474.

The product of its (nonzero) digits is 93312, while the sum is 43.

The square root of 823809931 is about 28702.0893141945. The cubic root of 823809931 is about 937.4375400402.

The spelling of 823809931 in words is "eight hundred twenty-three million, eight hundred nine thousand, nine hundred thirty-one".