16689394 has 4 divisors (see below), whose sum is σ = 25034094. Its totient is φ = 8344696.

The previous prime is 16689383. The next prime is 16689397. The reversal of 16689394 is 49398661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 49398661 = 13 ⋅3799897.

It can be written as a sum of positive squares in only one way, i.e., 16104169 + 585225 = 4013^2 + 765^2 .

It is not an unprimeable number, because it can be changed into a prime (16689397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4172347 + ... + 4172350.

Almost surely, 2^16689394 is an apocalyptic number.

16689394 is a deficient number, since it is larger than the sum of its proper divisors (8344700).

16689394 is an equidigital number, since it uses as much as digits as its factorization.

16689394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8344699.

The product of its digits is 279936, while the sum is 46.

The square root of 16689394 is about 4085.2654748498. The cubic root of 16689394 is about 255.5525325274.

The spelling of 16689394 in words is "sixteen million, six hundred eighty-nine thousand, three hundred ninety-four".