20905045 has 16 divisors (see below), whose sum is σ = 29917440. Its totient is φ = 13711104.

The previous prime is 20905033. The next prime is 20905051. The reversal of 20905045 is 54050902.

It is a cyclic number.

It is not a de Polignac number, because 20905045 - 2¹³ = 20896853 is a prime.

It is a congruent 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, 12180 + ... + 13789.

It is an arithmetic number, because the mean of its divisors is an integer number (1869840).

Almost surely, 2^20905045 is an apocalyptic number.

It is an amenable number.

20905045 is a deficient number, since it is larger than the sum of its proper divisors (9012395).

20905045 is a wasteful number, since it uses less digits than its factorization.

20905045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26004.

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

The square root of 20905045 is about 4572.2035169052. The cubic root of 20905045 is about 275.4759581261.

Adding to 20905045 its reverse (54050902), we get a palindrome (74955947).

The spelling of 20905045 in words is "twenty million, nine hundred five thousand, forty-five".