20439818 has 16 divisors (see below), whose sum is σ = 35126784. Its totient is φ = 8738160.

The previous prime is 20439803. The next prime is 20439841. The reversal of 20439818 is 81893402.

It is a happy number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 4871 + ... + 8037.

It is an arithmetic number, because the mean of its divisors is an integer number (2195424).

Almost surely, 2^20439818 is an apocalyptic number.

20439818 is a deficient number, since it is larger than the sum of its proper divisors (14686966).

20439818 is a wasteful number, since it uses less digits than its factorization.

20439818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3637.

The product of its (nonzero) digits is 13824, while the sum is 35.

The square root of 20439818 is about 4521.0416941232. The cubic root of 20439818 is about 273.4171013659.

The spelling of 20439818 in words is "twenty million, four hundred thirty-nine thousand, eight hundred eighteen".