20443989 has 4 divisors (see below), whose sum is σ = 27258656. Its totient is φ = 13629324.

The previous prime is 20443957. The next prime is 20443999. The reversal of 20443989 is 98934402.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 20443989 - 2⁵ = 20443957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20443909) 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, 3407329 + ... + 3407334.

It is an arithmetic number, because the mean of its divisors is an integer number (6814664).

Almost surely, 2^20443989 is an apocalyptic number.

It is an amenable number.

20443989 is a deficient number, since it is larger than the sum of its proper divisors (6814667).

20443989 is an equidigital number, since it uses as much as digits as its factorization.

20443989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6814666.

The product of its (nonzero) digits is 62208, while the sum is 39.

The square root of 20443989 is about 4521.5029580882. The cubic root of 20443989 is about 273.4356981585.

The spelling of 20443989 in words is "twenty million, four hundred forty-three thousand, nine hundred eighty-nine".