20804638 has 4 divisors (see below), whose sum is σ = 31206960. Its totient is φ = 10402318.

The previous prime is 20804611. The next prime is 20804653. The reversal of 20804638 is 83640802.

It is a happy number.

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

It is a super-2 number, since 2×20804638² = 865665924622088, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5201158 + ... + 5201161.

It is an arithmetic number, because the mean of its divisors is an integer number (7801740).

Almost surely, 2^20804638 is an apocalyptic number.

20804638 is a deficient number, since it is larger than the sum of its proper divisors (10402322).

20804638 is a wasteful number, since it uses less digits than its factorization.

20804638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10402321.

The product of its (nonzero) digits is 9216, while the sum is 31.

The square root of 20804638 is about 4561.2101464414. The cubic root of 20804638 is about 275.0342128233.

The spelling of 20804638 in words is "twenty million, eight hundred four thousand, six hundred thirty-eight".