18939446 has 4 divisors (see below), whose sum is σ = 28409172. Its totient is φ = 9469722.

The previous prime is 18939443. The next prime is 18939457. The reversal of 18939446 is 64493981.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 64493981 = 31 ⋅2080451.

It is a super-2 number, since 2×18939446² = 717405229573832, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18939397 and 18939406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18939443) 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 as a sum of consecutive naturals, namely, 4734860 + ... + 4734863.

It is an arithmetic number, because the mean of its divisors is an integer number (7102293).

Almost surely, 2^18939446 is an apocalyptic number.

18939446 is a deficient number, since it is larger than the sum of its proper divisors (9469726).

18939446 is an equidigital number, since it uses as much as digits as its factorization.

18939446 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9469725.

The product of its digits is 186624, while the sum is 44.

The square root of 18939446 is about 4351.9473801966. The cubic root of 18939446 is about 266.5563853016.

The spelling of 18939446 in words is "eighteen million, nine hundred thirty-nine thousand, four hundred forty-six".