20678909 has 8 divisors (see below), whose sum is σ = 21634560. Its totient is φ = 19728016.

The previous prime is 20678899. The next prime is 20678921. The reversal of 20678909 is 90987602.

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

It is a cyclic number.

It is not a de Polignac number, because 20678909 - 2²⁴ = 3901693 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 (20678809) 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, 10079 + ... + 11955.

It is an arithmetic number, because the mean of its divisors is an integer number (2704320).

Almost surely, 2^20678909 is an apocalyptic number.

It is an amenable number.

20678909 is a deficient number, since it is larger than the sum of its proper divisors (955651).

20678909 is a wasteful number, since it uses less digits than its factorization.

20678909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2379.

The product of its (nonzero) digits is 54432, while the sum is 41.

The square root of 20678909 is about 4547.4068434658. The cubic root of 20678909 is about 274.4790534369.

The spelling of 20678909 in words is "twenty million, six hundred seventy-eight thousand, nine hundred nine".