20404005 has 16 divisors (see below), whose sum is σ = 34365120. Its totient is φ = 10309248.

The previous prime is 20403989. The next prime is 20404009. The reversal of 20404005 is 50040402.

It is not a de Polignac number, because 20404005 - 2⁴ = 20403989 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20404009) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35512 + ... + 36081.

It is an arithmetic number, because the mean of its divisors is an integer number (2147820).

Almost surely, 2^20404005 is an apocalyptic number.

It is an amenable number.

20404005 is a deficient number, since it is larger than the sum of its proper divisors (13961115).

20404005 is a wasteful number, since it uses less digits than its factorization.

20404005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71620.

The product of its (nonzero) digits is 160, while the sum is 15.

The square root of 20404005 is about 4517.0792554481. The cubic root of 20404005 is about 273.2573215499.

Adding to 20404005 its reverse (50040402), we get a palindrome (70444407).

The spelling of 20404005 in words is "twenty million, four hundred four thousand, five".