20813969 has 8 divisors (see below), whose sum is σ = 22941408. Its totient is φ = 18725760.

The previous prime is 20813963. The next prime is 20813971. The reversal of 20813969 is 96931802.

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 20813969 - 2⁴ = 20813953 is a prime.

It is a super-2 number, since 2×20813969² = 866442611065922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20813963) 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, 8687 + ... + 10820.

It is an arithmetic number, because the mean of its divisors is an integer number (2867676).

Almost surely, 2^20813969 is an apocalyptic number.

It is an amenable number.

20813969 is a deficient number, since it is larger than the sum of its proper divisors (2127439).

20813969 is a wasteful number, since it uses less digits than its factorization.

20813969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19615.

The product of its (nonzero) digits is 23328, while the sum is 38.

The square root of 20813969 is about 4562.2328962910. The cubic root of 20813969 is about 275.0753248206.

The spelling of 20813969 in words is "twenty million, eight hundred thirteen thousand, nine hundred sixty-nine".