20669689 has 4 divisors (see below), whose sum is σ = 20719440. Its totient is φ = 20619940.

The previous prime is 20669683. The next prime is 20669729. The reversal of 20669689 is 98696602.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20669689 - 2³ = 20669681 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20669681) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24247 + ... + 25084.

It is an arithmetic number, because the mean of its divisors is an integer number (5179860).

Almost surely, 2^20669689 is an apocalyptic number.

It is an amenable number.

20669689 is a deficient number, since it is larger than the sum of its proper divisors (49751).

20669689 is an equidigital number, since it uses as much as digits as its factorization.

20669689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49750.

The product of its (nonzero) digits is 279936, while the sum is 46.

The square root of 20669689 is about 4546.3929658577. The cubic root of 20669689 is about 274.4382538460.

The spelling of 20669689 in words is "twenty million, six hundred sixty-nine thousand, six hundred eighty-nine".