20443997 has 4 divisors (see below), whose sum is σ = 23364576. Its totient is φ = 17523420.

The previous prime is 20443957. The next prime is 20443999. The reversal of 20443997 is 79934402.

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 a cyclic number.

It is not a de Polignac number, because 20443997 - 2⁶ = 20443933 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 20443997.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20443999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1460279 + ... + 1460292.

It is an arithmetic number, because the mean of its divisors is an integer number (5841144).

Almost surely, 2^20443997 is an apocalyptic number.

It is an amenable number.

20443997 is a deficient number, since it is larger than the sum of its proper divisors (2920579).

20443997 is an equidigital number, since it uses as much as digits as its factorization.

20443997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2920578.

The product of its (nonzero) digits is 54432, while the sum is 38.

The square root of 20443997 is about 4521.5038427497. The cubic root of 20443997 is about 273.4357338248.

The spelling of 20443997 in words is "twenty million, four hundred forty-three thousand, nine hundred ninety-seven".