20816838 has 96 divisors (see below), whose sum is σ = 55560960. Its totient is φ = 5715360.

The previous prime is 20816821. The next prime is 20816839. The reversal of 20816838 is 83861802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20816839) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 98553 + ... + 98763.

It is an arithmetic number, because the mean of its divisors is an integer number (578760).

Almost surely, 2^20816838 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20816838, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27780480).

20816838 is an abundant number, since it is smaller than the sum of its proper divisors (34744122).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20816838 is a wasteful number, since it uses less digits than its factorization.

20816838 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 264 (or 252 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 20816838 is about 4562.5473148232. The cubic root of 20816838 is about 275.0879630452.

The spelling of 20816838 in words is "twenty million, eight hundred sixteen thousand, eight hundred thirty-eight".