816884609 has 4 divisors (see below), whose sum is σ = 818244420. Its totient is φ = 815524800.

The previous prime is 816884599. The next prime is 816884617. The reversal of 816884609 is 906488618.

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 373571584 + 443313025 = 19328^2 + 21055^2 .

It is a cyclic number.

It is not a de Polignac number, because 816884609 - 2¹² = 816880513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (816884639) 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, 679004 + ... + 680205.

It is an arithmetic number, because the mean of its divisors is an integer number (204561105).

Almost surely, 2^816884609 is an apocalyptic number.

It is an amenable number.

816884609 is a deficient number, since it is larger than the sum of its proper divisors (1359811).

816884609 is a wasteful number, since it uses less digits than its factorization.

816884609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1359810.

The product of its (nonzero) digits is 663552, while the sum is 50.

The square root of 816884609 is about 28581.1932745993. The cubic root of 816884609 is about 934.8033021560.

The spelling of 816884609 in words is "eight hundred sixteen million, eight hundred eighty-four thousand, six hundred nine".