20113821 has 48 divisors (see below), whose sum is σ = 36691200. Its totient is φ = 10333440.

The previous prime is 20113817. The next prime is 20113843. The reversal of 20113821 is 12831102.

It is not a de Polignac number, because 20113821 - 2² = 20113817 is a prime.

It is a super-3 number, since 3×20113821³ (a number of 23 digits) contains 333 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20113794 and 20113803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20113861) 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, 33280 + ... + 33878.

It is an arithmetic number, because the mean of its divisors is an integer number (764400).

Almost surely, 2^20113821 is an apocalyptic number.

20113821 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20113821 is a deficient number, since it is larger than the sum of its proper divisors (16577379).

20113821 is a wasteful number, since it uses less digits than its factorization.

20113821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 666 (or 663 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

The square root of 20113821 is about 4484.8434755296. The cubic root of 20113821 is about 271.9557174522.

Adding to 20113821 its reverse (12831102), we get a palindrome (32944923).

It can be divided in two parts, 2011 and 3821, that added together give a cube (5832 = 18³).

The spelling of 20113821 in words is "twenty million, one hundred thirteen thousand, eight hundred twenty-one".