20008505 has 16 divisors (see below), whose sum is σ = 27333504. Its totient is φ = 13918080.

The previous prime is 20008487. The next prime is 20008523. The reversal of 20008505 is 50580002.

It is an interprime number because it is at equal distance from previous prime (20008487) and next prime (20008523).

It is not a de Polignac number, because 20008505 - 2⁸ = 20008249 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6644 + ... + 9173.

It is an arithmetic number, because the mean of its divisors is an integer number (1708344).

Almost surely, 2^20008505 is an apocalyptic number.

It is an amenable number.

20008505 is a deficient number, since it is larger than the sum of its proper divisors (7324999).

20008505 is a wasteful number, since it uses less digits than its factorization.

20008505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15856.

The product of its (nonzero) digits is 400, while the sum is 20.

The square root of 20008505 is about 4473.0867418372. The cubic root of 20008505 is about 271.4802330764.

Adding to 20008505 its reverse (50580002), we get a palindrome (70588507).

The spelling of 20008505 in words is "twenty million, eight thousand, five hundred five".