20017855 has 16 divisors (see below), whose sum is σ = 28221984. Its totient is φ = 13438080.

The previous prime is 20017853. The next prime is 20017871. The reversal of 20017855 is 55871002.

It is not a de Polignac number, because 20017855 - 2¹ = 20017853 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20017853) 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, 13284 + ... + 14713.

It is an arithmetic number, because the mean of its divisors is an integer number (1763874).

Almost surely, 2^20017855 is an apocalyptic number.

20017855 is a deficient number, since it is larger than the sum of its proper divisors (8204129).

20017855 is a wasteful number, since it uses less digits than its factorization.

20017855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28026.

The product of its (nonzero) digits is 2800, while the sum is 28.

The square root of 20017855 is about 4474.1317593473. The cubic root of 20017855 is about 271.5225141779.

Adding to 20017855 its reverse (55871002), we get a palindrome (75888857).

The spelling of 20017855 in words is "twenty million, seventeen thousand, eight hundred fifty-five".