20443621 has 8 divisors (see below), whose sum is σ = 22500864. Its totient is φ = 18419520.

The previous prime is 20443613. The next prime is 20443627. The reversal of 20443621 is 12634402.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 20443621 - 2³ = 20443613 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20443592 and 20443601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20443627) 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, 6981 + ... + 9466.

It is an arithmetic number, because the mean of its divisors is an integer number (2812608).

Almost surely, 2^20443621 is an apocalyptic number.

It is an amenable number.

20443621 is a deficient number, since it is larger than the sum of its proper divisors (2057243).

20443621 is a wasteful number, since it uses less digits than its factorization.

20443621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16571.

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 20443621 is about 4521.4622634719. The cubic root of 20443621 is about 273.4340574979.

It can be divided in two parts, 2044 and 3621, that added together give a palindrome (5665).

The spelling of 20443621 in words is "twenty million, four hundred forty-three thousand, six hundred twenty-one".