18989494 has 4 divisors (see below), whose sum is σ = 28484244. Its totient is φ = 9494746.

The previous prime is 18989491. The next prime is 18989501. The reversal of 18989494 is 49498981.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 49498981 = 7 ⋅7071283.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18989491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4747372 + ... + 4747375.

It is an arithmetic number, because the mean of its divisors is an integer number (7121061).

Almost surely, 2^18989494 is an apocalyptic number.

18989494 is a deficient number, since it is larger than the sum of its proper divisors (9494750).

18989494 is an equidigital number, since it uses as much as digits as its factorization.

18989494 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9494749.

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

The square root of 18989494 is about 4357.6936560525. The cubic root of 18989494 is about 266.7909729486.

The spelling of 18989494 in words is "eighteen million, nine hundred eighty-nine thousand, four hundred ninety-four".