813505243 has 4 divisors (see below), whose sum is σ = 815285800. Its totient is φ = 811724688.

The previous prime is 813505237. The next prime is 813505249. The reversal of 813505243 is 342505318.

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

It is an interprime number because it is at equal distance from previous prime (813505237) and next prime (813505249).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-813505243 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (813505249) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 889593 + ... + 890506.

It is an arithmetic number, because the mean of its divisors is an integer number (203821450).

Almost surely, 2^813505243 is an apocalyptic number.

813505243 is a deficient number, since it is larger than the sum of its proper divisors (1780557).

813505243 is a wasteful number, since it uses less digits than its factorization.

813505243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1780556.

The product of its (nonzero) digits is 14400, while the sum is 31.

The square root of 813505243 is about 28522.0133055154. The cubic root of 813505243 is about 933.5124593981.

The spelling of 813505243 in words is "eight hundred thirteen million, five hundred five thousand, two hundred forty-three".