18910309 has 16 divisors (see below), whose sum is σ = 21381120. Its totient is φ = 16576560.

The previous prime is 18910289. The next prime is 18910321. The reversal of 18910309 is 90301981.

It is not a de Polignac number, because 18910309 - 2⁷ = 18910181 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 (18910369) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40612 + ... + 41074.

It is an arithmetic number, because the mean of its divisors is an integer number (1336320).

Almost surely, 2^18910309 is an apocalyptic number.

It is an amenable number.

18910309 is a deficient number, since it is larger than the sum of its proper divisors (2470811).

18910309 is a wasteful number, since it uses less digits than its factorization.

18910309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 600.

The product of its (nonzero) digits is 1944, while the sum is 31.

The square root of 18910309 is about 4348.5985098650. The cubic root of 18910309 is about 266.4196224202.

The spelling of 18910309 in words is "eighteen million, nine hundred ten thousand, three hundred nine".