815881229 has 4 divisors (see below), whose sum is σ = 815951100. Its totient is φ = 815811360.

The previous prime is 815881217. The next prime is 815881247. The reversal of 815881229 is 922188518.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 576096004 + 239785225 = 24002^2 + 15485^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-815881229 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 815881229.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (815881249) 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, 12704 + ... + 42345.

It is an arithmetic number, because the mean of its divisors is an integer number (203987775).

Almost surely, 2^815881229 is an apocalyptic number.

It is an amenable number.

815881229 is a deficient number, since it is larger than the sum of its proper divisors (69871).

815881229 is a wasteful number, since it uses less digits than its factorization.

815881229 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69870.

The product of its digits is 92160, while the sum is 44.

The square root of 815881229 is about 28563.6347301950. The cubic root of 815881229 is about 934.4204054683.

The spelling of 815881229 in words is "eight hundred fifteen million, eight hundred eighty-one thousand, two hundred twenty-nine".