20500005 has 8 divisors (see below), whose sum is σ = 32800032. Its totient is φ = 10933328.

The previous prime is 20499971. The next prime is 20500019. The reversal of 20500005 is 50000502.

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 20500005 - 2⁸ = 20499749 is a prime.

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, 683319 + ... + 683348.

It is an arithmetic number, because the mean of its divisors is an integer number (4100004).

Almost surely, 2^20500005 is an apocalyptic number.

It is an amenable number.

20500005 is a deficient number, since it is larger than the sum of its proper divisors (12300027).

20500005 is a wasteful number, since it uses less digits than its factorization.

20500005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1366675.

The product of its (nonzero) digits is 50, while the sum is 12.

The square root of 20500005 is about 4527.6931212263. The cubic root of 20500005 is about 273.6852059907.

Adding to 20500005 its reverse (50000502), we get a palindrome (70500507).

The spelling of 20500005 in words is "twenty million, five hundred thousand, five".