20149209 has 8 divisors (see below), whose sum is σ = 29850720. Its totient is φ = 13432788.

The previous prime is 20149193. The next prime is 20149211. The reversal of 20149209 is 90294102.

It is not a de Polignac number, because 20149209 - 2⁴ = 20149193 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 746267 = 20149209 / (2 + 0 + 1 + 4 + 9 + 2 + 0 + 9).

It is not an unprimeable number, because it can be changed into a prime (20149009) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 373107 + ... + 373160.

It is an arithmetic number, because the mean of its divisors is an integer number (3731340).

Almost surely, 2^20149209 is an apocalyptic number.

It is an amenable number.

20149209 is a deficient number, since it is larger than the sum of its proper divisors (9701511).

20149209 is an equidigital number, since it uses as much as digits as its factorization.

20149209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 746276 (or 746270 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 20149209 is about 4488.7870299224. The cubic root of 20149209 is about 272.1151158139.

The spelling of 20149209 in words is "twenty million, one hundred forty-nine thousand, two hundred nine".