815241913 has 4 divisors (see below), whose sum is σ = 819954468. Its totient is φ = 810529360.

The previous prime is 815241901. The next prime is 815241929. The reversal of 815241913 is 319142518.

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

It can be written as a sum of positive squares in 2 ways, for example, as 789160464 + 26081449 = 28092^2 + 5107^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-815241913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (815241013) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2356018 + ... + 2356363.

It is an arithmetic number, because the mean of its divisors is an integer number (204988617).

Almost surely, 2^815241913 is an apocalyptic number.

It is an amenable number.

815241913 is a deficient number, since it is larger than the sum of its proper divisors (4712555).

815241913 is a wasteful number, since it uses less digits than its factorization.

815241913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4712554.

The product of its digits is 8640, while the sum is 34.

The square root of 815241913 is about 28552.4414542785. The cubic root of 815241913 is about 934.1762743379.

The spelling of 815241913 in words is "eight hundred fifteen million, two hundred forty-one thousand, nine hundred thirteen".