816389869 has 4 divisors (see below), whose sum is σ = 817196796. Its totient is φ = 815582944.

The previous prime is 816389839. The next prime is 816389881. The reversal of 816389869 is 968983618.

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 342805225 + 473584644 = 18515^2 + 21762^2 .

It is a cyclic number.

It is not a de Polignac number, because 816389869 - 2⁷ = 816389741 is a prime.

It is a super-2 number, since 2×816389869² = 1332984836411674322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (816389839) 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, 401944 + ... + 403969.

It is an arithmetic number, because the mean of its divisors is an integer number (204299199).

Almost surely, 2^816389869 is an apocalyptic number.

It is an amenable number.

816389869 is a deficient number, since it is larger than the sum of its proper divisors (806927).

816389869 is a wasteful number, since it uses less digits than its factorization.

816389869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 806926.

The product of its digits is 4478976, while the sum is 58.

The square root of 816389869 is about 28572.5369717146. The cubic root of 816389869 is about 934.6145451889.

The spelling of 816389869 in words is "eight hundred sixteen million, three hundred eighty-nine thousand, eight hundred sixty-nine".