20204639 has 8 divisors (see below), whose sum is σ = 24867360. Its totient is φ = 15986016.

The previous prime is 20204633. The next prime is 20204641. The reversal of 20204639 is 93640202.

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

It is a cyclic number.

It is not a de Polignac number, because 20204639 - 2²⁰ = 19156063 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20204633) 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, 110924 + ... + 111105.

It is an arithmetic number, because the mean of its divisors is an integer number (3108420).

Almost surely, 2^20204639 is an apocalyptic number.

20204639 is a deficient number, since it is larger than the sum of its proper divisors (4662721).

20204639 is a wasteful number, since it uses less digits than its factorization.

20204639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222049.

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 20204639 is about 4494.9570631987. The cubic root of 20204639 is about 272.3644147759.

The spelling of 20204639 in words is "twenty million, two hundred four thousand, six hundred thirty-nine".