20813838 has 16 divisors (see below), whose sum is σ = 41841360. Its totient is φ = 6902336.

The previous prime is 20813813. The next prime is 20813839. The reversal of 20813838 is 83831802.

It is a junction number, because it is equal to n+sod(n) for n = 20813799 and 20813808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20813839) 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, 7623 + ... + 9986.

It is an arithmetic number, because the mean of its divisors is an integer number (2615085).

Almost surely, 2^20813838 is an apocalyptic number.

20813838 is an abundant number, since it is smaller than the sum of its proper divisors (21027522).

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

20813838 is a wasteful number, since it uses less digits than its factorization.

20813838 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17811.

The product of its (nonzero) digits is 9216, while the sum is 33.

The square root of 20813838 is about 4562.2185392635. The cubic root of 20813838 is about 275.0747477251.

The spelling of 20813838 in words is "twenty million, eight hundred thirteen thousand, eight hundred thirty-eight".