20909867 has 8 divisors (see below), whose sum is σ = 22848240. Its totient is φ = 18977760.

The previous prime is 20909857. The next prime is 20909869. The reversal of 20909867 is 76890902.

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 20909867 - 2⁴ = 20909851 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20909869) 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, 7973 + ... + 10265.

It is an arithmetic number, because the mean of its divisors is an integer number (2856030).

Almost surely, 2^20909867 is an apocalyptic number.

20909867 is a deficient number, since it is larger than the sum of its proper divisors (1938373).

20909867 is a wasteful number, since it uses less digits than its factorization.

20909867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3133.

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

The square root of 20909867 is about 4572.7308033603. The cubic root of 20909867 is about 275.4971371119.

The spelling of 20909867 in words is "twenty million, nine hundred nine thousand, eight hundred sixty-seven".