20045905 has 8 divisors (see below), whose sum is σ = 26241984. Its totient is φ = 14578800.

The previous prime is 20045887. The next prime is 20045929. The reversal of 20045905 is 50954002.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20045905 - 2⁷ = 20045777 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20045905.

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, 182181 + ... + 182290.

It is an arithmetic number, because the mean of its divisors is an integer number (3280248).

Almost surely, 2^20045905 is an apocalyptic number.

It is an amenable number.

20045905 is a deficient number, since it is larger than the sum of its proper divisors (6196079).

20045905 is a wasteful number, since it uses less digits than its factorization.

20045905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 364487.

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 20045905 is about 4477.2653484019. The cubic root of 20045905 is about 271.6492785405.

Adding to 20045905 its reverse (50954002), we get a palindrome (70999907).

The spelling of 20045905 in words is "twenty million, forty-five thousand, nine hundred five".