20989205 has 8 divisors (see below), whose sum is σ = 26512800. Its totient is φ = 15907536.

The previous prime is 20989193. The next prime is 20989207. The reversal of 20989205 is 50298902.

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 20989205 - 2¹⁸ = 20727061 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20989207) 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, 110375 + ... + 110564.

It is an arithmetic number, because the mean of its divisors is an integer number (3314100).

Almost surely, 2^20989205 is an apocalyptic number.

It is an amenable number.

20989205 is a deficient number, since it is larger than the sum of its proper divisors (5523595).

20989205 is a wasteful number, since it uses less digits than its factorization.

20989205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220963.

The product of its (nonzero) digits is 12960, while the sum is 35.

The square root of 20989205 is about 4581.3977124891. The cubic root of 20989205 is about 275.8451355886.

The spelling of 20989205 in words is "twenty million, nine hundred eighty-nine thousand, two hundred five".