18989405 has 8 divisors (see below), whose sum is σ = 22879584. Its totient is φ = 15130000.

The previous prime is 18989401. The next prime is 18989413. The reversal of 18989405 is 50498981.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18989405 - 2² = 18989401 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 (18989401) 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 7 ways as a sum of consecutive naturals, for example, 6311 + ... + 8820.

It is an arithmetic number, because the mean of its divisors is an integer number (2859948).

Almost surely, 2^18989405 is an apocalyptic number.

It is an amenable number.

18989405 is a deficient number, since it is larger than the sum of its proper divisors (3890179).

18989405 is a wasteful number, since it uses less digits than its factorization.

18989405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15387.

The product of its (nonzero) digits is 103680, while the sum is 44.

The square root of 18989405 is about 4357.6834442167. The cubic root of 18989405 is about 266.7905561491.

The spelling of 18989405 in words is "eighteen million, nine hundred eighty-nine thousand, four hundred five".