816689194 has 16 divisors (see below), whose sum is σ = 1243800648. Its totient is φ = 402135552.

The previous prime is 816689191. The next prime is 816689227. The reversal of 816689194 is 491986618.

It can be written as a sum of positive squares in 4 ways, for example, as 387577969 + 429111225 = 19687^2 + 20715^2 .

It is not an unprimeable number, because it can be changed into a prime (816689191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23974 + ... + 46990.

Almost surely, 2^816689194 is an apocalyptic number.

816689194 is a deficient number, since it is larger than the sum of its proper divisors (427111454).

816689194 is a wasteful number, since it uses less digits than its factorization.

816689194 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23289.

The product of its digits is 746496, while the sum is 52.

The square root of 816689194 is about 28577.7744759805. The cubic root of 816689194 is about 934.7287550479.

The spelling of 816689194 in words is "eight hundred sixteen million, six hundred eighty-nine thousand, one hundred ninety-four".