831691813 has 2 divisors, whose sum is σ = 831691814. Its totient is φ = 831691812.

The previous prime is 831691801. The next prime is 831691823. The reversal of 831691813 is 318196138.

It is the 11774-th star number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 612711009 + 218980804 = 24753^2 + 14798^2 .

It is a cyclic number.

It is not a de Polignac number, because 831691813 - 2¹³ = 831683621 is a prime.

It is a super-2 number, since 2×831691813² = 1383422543622453938, which contains 22 as substring.

It is equal to p_42690739 and since 831691813 and 42690739 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (831691823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 415845906 + 415845907.

It is an arithmetic number, because the mean of its divisors is an integer number (415845907).

Almost surely, 2^831691813 is an apocalyptic number.

It is an amenable number.

831691813 is a deficient number, since it is larger than the sum of its proper divisors (1).

831691813 is an equidigital number, since it uses as much as digits as its factorization.

831691813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 31104, while the sum is 40.

The square root of 831691813 is about 28839.0674779890. The cubic root of 831691813 is about 940.4177308133.

The spelling of 831691813 in words is "eight hundred thirty-one million, six hundred ninety-one thousand, eight hundred thirteen".