18679989 has 4 divisors (see below), whose sum is σ = 24906656. Its totient is φ = 12453324.

The previous prime is 18679987. The next prime is 18679993. The reversal of 18679989 is 98997681.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 18679989 - 2¹ = 18679987 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18679987) 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 in 3 ways as a sum of consecutive naturals, for example, 3113329 + ... + 3113334.

It is an arithmetic number, because the mean of its divisors is an integer number (6226664).

Almost surely, 2^18679989 is an apocalyptic number.

It is an amenable number.

18679989 is a deficient number, since it is larger than the sum of its proper divisors (6226667).

18679989 is an equidigital number, since it uses as much as digits as its factorization.

18679989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6226666.

The product of its digits is 1959552, while the sum is 57.

The square root of 18679989 is about 4322.0352844464. The cubic root of 18679989 is about 265.3335730507. Note that the first 3 decimals are identical.

The spelling of 18679989 in words is "eighteen million, six hundred seventy-nine thousand, nine hundred eighty-nine".