20804005 has 8 divisors (see below), whose sum is σ = 26433432. Its totient is φ = 15664128.

The previous prime is 20803987. The next prime is 20804053. The reversal of 20804005 is 50040802.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 3448449 + 17355556 = 1857^2 + 4166^2 .

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 20804005 - 2⁷ = 20803877 is a prime.

It is a super-3 number, since 3×20804005³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 122292 + ... + 122461.

It is an arithmetic number, because the mean of its divisors is an integer number (3304179).

Almost surely, 2^20804005 is an apocalyptic number.

It is an amenable number.

20804005 is a deficient number, since it is larger than the sum of its proper divisors (5629427).

20804005 is a wasteful number, since it uses less digits than its factorization.

20804005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244775.

The product of its (nonzero) digits is 320, while the sum is 19.

The square root of 20804005 is about 4561.1407564336. The cubic root of 20804005 is about 275.0314234065.

Adding to 20804005 its reverse (50040802), we get a palindrome (70844807).

It can be divided in two parts, 20 and 804005, that multiplied together give a square (16080100 = 4010²).

The spelling of 20804005 in words is "twenty million, eight hundred four thousand, five".