816115897 has 4 divisors (see below), whose sum is σ = 816508660. Its totient is φ = 815723136.

The previous prime is 816115841. The next prime is 816115901. The reversal of 816115897 is 798511618.

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 703522576 + 112593321 = 26524^2 + 10611^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-816115897 is a prime.

It is a super-2 number, since 2×816115897² = 1332090314672229218, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (816115297) 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, 193248 + ... + 197425.

It is an arithmetic number, because the mean of its divisors is an integer number (204127165).

Almost surely, 2^816115897 is an apocalyptic number.

It is an amenable number.

816115897 is a deficient number, since it is larger than the sum of its proper divisors (392763).

816115897 is a wasteful number, since it uses less digits than its factorization.

816115897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 392762.

The product of its digits is 120960, while the sum is 46.

The square root of 816115897 is about 28567.7422454068. The cubic root of 816115897 is about 934.5099844985.

The spelling of 816115897 in words is "eight hundred sixteen million, one hundred fifteen thousand, eight hundred ninety-seven".