20969789 has 8 divisors (see below), whose sum is σ = 22249080. Its totient is φ = 19695616.

The previous prime is 20969783. The next prime is 20969791. The reversal of 20969789 is 98796902.

It can be written as a sum of positive squares in 4 ways, for example, as 3034564 + 17935225 = 1742^2 + 4235^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20969789 is a prime.

It is a super-3 number, since 3×20969789³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20969783) 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, 10157 + ... + 12045.

It is an arithmetic number, because the mean of its divisors is an integer number (2781135).

Almost surely, 2^20969789 is an apocalyptic number.

It is an amenable number.

20969789 is a deficient number, since it is larger than the sum of its proper divisors (1279291).

20969789 is a wasteful number, since it uses less digits than its factorization.

20969789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2559.

The product of its (nonzero) digits is 489888, while the sum is 50.

The square root of 20969789 is about 4579.2782182348. The cubic root of 20969789 is about 275.7600527812.

The spelling of 20969789 in words is "twenty million, nine hundred sixty-nine thousand, seven hundred eighty-nine".