20443615 has 4 divisors (see below), whose sum is σ = 24532344. Its totient is φ = 16354888.

The previous prime is 20443613. The next prime is 20443627. The reversal of 20443615 is 51634402.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20443615 - 2¹ = 20443613 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20443615.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20443613) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2044357 + ... + 2044366.

It is an arithmetic number, because the mean of its divisors is an integer number (6133086).

Almost surely, 2^20443615 is an apocalyptic number.

20443615 is a deficient number, since it is larger than the sum of its proper divisors (4088729).

20443615 is an equidigital number, since it uses as much as digits as its factorization.

20443615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4088728.

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 20443615 is about 4521.4615999696. The cubic root of 20443615 is about 273.4340307478.

The spelling of 20443615 in words is "twenty million, four hundred forty-three thousand, six hundred fifteen".