20489939 has 4 divisors (see below), whose sum is σ = 20504256. Its totient is φ = 20475624.

The previous prime is 20489927. The next prime is 20489957. The reversal of 20489939 is 93998402.

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 20489939 - 2⁸ = 20489683 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 20489939.

It is not an unprimeable number, because it can be changed into a prime (20489969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4739 + ... + 7964.

It is an arithmetic number, because the mean of its divisors is an integer number (5126064).

Almost surely, 2^20489939 is an apocalyptic number.

20489939 is a deficient number, since it is larger than the sum of its proper divisors (14317).

20489939 is a wasteful number, since it uses less digits than its factorization.

20489939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14316.

The product of its (nonzero) digits is 139968, while the sum is 44.

The square root of 20489939 is about 4526.5813811308. The cubic root of 20489939 is about 273.6404032973.

The spelling of 20489939 in words is "twenty million, four hundred eighty-nine thousand, nine hundred thirty-nine".