20404239 has 8 divisors (see below), whose sum is σ = 27234480. Its totient is φ = 13588416.

The previous prime is 20404213. The next prime is 20404249. The reversal of 20404239 is 93240402.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20404239 - 2⁹ = 20403727 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20404249) 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 7 ways as a sum of consecutive naturals, for example, 307 + ... + 6395.

It is an arithmetic number, because the mean of its divisors is an integer number (3404310).

Almost surely, 2^20404239 is an apocalyptic number.

20404239 is a deficient number, since it is larger than the sum of its proper divisors (6830241).

20404239 is a wasteful number, since it uses less digits than its factorization.

20404239 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7209.

The product of its (nonzero) digits is 1728, while the sum is 24.

The square root of 20404239 is about 4517.1051570669. The cubic root of 20404239 is about 273.2583661483.

The spelling of 20404239 in words is "twenty million, four hundred four thousand, two hundred thirty-nine".