16639894 has 4 divisors (see below), whose sum is σ = 24959844. Its totient is φ = 8319946.

The previous prime is 16639871. The next prime is 16639937. The reversal of 16639894 is 49893661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 49893661 = 1231 ⋅40531.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4159972 + ... + 4159975.

It is an arithmetic number, because the mean of its divisors is an integer number (6239961).

Almost surely, 2^16639894 is an apocalyptic number.

16639894 is a deficient number, since it is larger than the sum of its proper divisors (8319950).

16639894 is an equidigital number, since it uses as much as digits as its factorization.

16639894 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8319949.

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

The square root of 16639894 is about 4079.2026181596. The cubic root of 16639894 is about 255.2996298495.

The spelling of 16639894 in words is "sixteen million, six hundred thirty-nine thousand, eight hundred ninety-four".