20818169 has 4 divisors (see below), whose sum is σ = 20968080. Its totient is φ = 20668260.

The previous prime is 20818153. The next prime is 20818181. The reversal of 20818169 is 96181802.

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 20818169 - 2⁴ = 20818153 is a prime.

It is a super-2 number, since 2×20818169² = 866792321025122, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20818139) 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, 74747 + ... + 75024.

It is an arithmetic number, because the mean of its divisors is an integer number (5242020).

Almost surely, 2^20818169 is an apocalyptic number.

It is an amenable number.

20818169 is a deficient number, since it is larger than the sum of its proper divisors (149911).

20818169 is a wasteful number, since it uses less digits than its factorization.

20818169 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149910.

The product of its (nonzero) digits is 6912, while the sum is 35.

The square root of 20818169 is about 4562.6931739927. The cubic root of 20818169 is about 275.0938258356.

The spelling of 20818169 in words is "twenty million, eight hundred eighteen thousand, one hundred sixty-nine".