20838021 has 8 divisors (see below), whose sum is σ = 27809760. Its totient is φ = 13879152.

The previous prime is 20838019. The next prime is 20838043. The reversal of 20838021 is 12083802.

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

It is not a de Polignac number, because 20838021 - 2¹ = 20838019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20837982 and 20838000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20838011) 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, 1590 + ... + 6648.

It is an arithmetic number, because the mean of its divisors is an integer number (3476220).

Almost surely, 2^20838021 is an apocalyptic number.

It is an amenable number.

20838021 is a deficient number, since it is larger than the sum of its proper divisors (6971739).

20838021 is a wasteful number, since it uses less digits than its factorization.

20838021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6435.

The product of its (nonzero) digits is 768, while the sum is 24.

The square root of 20838021 is about 4564.8681251489. The cubic root of 20838021 is about 275.1812403059.

The spelling of 20838021 in words is "twenty million, eight hundred thirty-eight thousand, twenty-one".