20447903 has 4 divisors (see below), whose sum is σ = 23369040. Its totient is φ = 17526768.

The previous prime is 20447899. The next prime is 20447951. The reversal of 20447903 is 30974402.

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

It is not a de Polignac number, because 20447903 - 2² = 20447899 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 (20447953) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1460558 + ... + 1460571.

It is an arithmetic number, because the mean of its divisors is an integer number (5842260).

Almost surely, 2^20447903 is an apocalyptic number.

20447903 is a deficient number, since it is larger than the sum of its proper divisors (2921137).

20447903 is an equidigital number, since it uses as much as digits as its factorization.

20447903 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2921136.

The product of its (nonzero) digits is 6048, while the sum is 29.

The square root of 20447903 is about 4521.9357580576. The cubic root of 20447903 is about 273.4531467923.

The spelling of 20447903 in words is "twenty million, four hundred forty-seven thousand, nine hundred three".