20800161 has 12 divisors (see below), whose sum is σ = 30778020. Its totient is φ = 13528320.

The previous prime is 20800159. The next prime is 20800177. The reversal of 20800161 is 16100802.

It can be written as a sum of positive squares in 2 ways, for example, as 1166400 + 19633761 = 1080^2 + 4431^2 .

It is not a de Polignac number, because 20800161 - 2¹ = 20800159 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20800111) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 27816 + ... + 28553.

It is an arithmetic number, because the mean of its divisors is an integer number (2564835).

Almost surely, 2^20800161 is an apocalyptic number.

It is an amenable number.

20800161 is a deficient number, since it is larger than the sum of its proper divisors (9977859).

20800161 is a wasteful number, since it uses less digits than its factorization.

20800161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56416 (or 56413 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

The square root of 20800161 is about 4560.7193511550. The cubic root of 20800161 is about 275.0144829838.

Adding to 20800161 its reverse (16100802), we get a palindrome (36900963).

The spelling of 20800161 in words is "twenty million, eight hundred thousand, one hundred sixty-one".