815140481 has 4 divisors (see below), whose sum is σ = 818639172. Its totient is φ = 811641792.

The previous prime is 815140471. The next prime is 815140511. The reversal of 815140481 is 184041518.

It is a happy number.

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 112042225 + 703098256 = 10585^2 + 26516^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-815140481 is a prime.

It is a super-2 number, since 2×815140481² = 1328908007529822722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (815140471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1748996 + ... + 1749461.

It is an arithmetic number, because the mean of its divisors is an integer number (204659793).

Almost surely, 2^815140481 is an apocalyptic number.

It is an amenable number.

815140481 is a deficient number, since it is larger than the sum of its proper divisors (3498691).

815140481 is a wasteful number, since it uses less digits than its factorization.

815140481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3498690.

The product of its (nonzero) digits is 5120, while the sum is 32.

The square root of 815140481 is about 28550.6651586263. The cubic root of 815140481 is about 934.1375294793.

Adding to 815140481 its reverse (184041518), we get a palindrome (999181999).

The spelling of 815140481 in words is "eight hundred fifteen million, one hundred forty thousand, four hundred eighty-one".