20443821 has 8 divisors (see below), whose sum is σ = 27373440. Its totient is φ = 13571712.

The previous prime is 20443807. The next prime is 20443823. The reversal of 20443821 is 12834402.

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

It is not a de Polignac number, because 20443821 - 2⁷ = 20443693 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20443791 and 20443800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20443823) 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, 13540 + ... + 14973.

It is an arithmetic number, because the mean of its divisors is an integer number (3421680).

Almost surely, 2^20443821 is an apocalyptic number.

It is an amenable number.

20443821 is a deficient number, since it is larger than the sum of its proper divisors (6929619).

20443821 is a wasteful number, since it uses less digits than its factorization.

20443821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28755.

The product of its (nonzero) digits is 1536, while the sum is 24.

The square root of 20443821 is about 4521.4843801566. The cubic root of 20443821 is about 273.4349491637.

The spelling of 20443821 in words is "twenty million, four hundred forty-three thousand, eight hundred twenty-one".