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20807201 = 171223953
BaseRepresentation
bin100111101011…
…1111000100001
31110011010010002
41033113320201
520311312301
62021545345
7341600252
oct117277041
943133102
1020807201
1110821838
126b75255
13440696c
142a98b29
151c6016b
hex13d7e21

20807201 has 4 divisors (see below), whose sum is σ = 22031172. Its totient is φ = 19583232.

The previous prime is 20807191. The next prime is 20807219. The reversal of 20807201 is 10270802.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 10270802 = 25135401.

It can be written as a sum of positive squares in 2 ways, for example, as 12967201 + 7840000 = 3601^2 + 2800^2 .

It is a cyclic number.

It is not a de Polignac number, because 20807201 - 214 = 20790817 is a prime.

It is a super-2 number, since 2×208072012 = 865879226908802, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20807251) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 611960 + ... + 611993.

It is an arithmetic number, because the mean of its divisors is an integer number (5507793).

Almost surely, 220807201 is an apocalyptic number.

It is an amenable number.

20807201 is a deficient number, since it is larger than the sum of its proper divisors (1223971).

20807201 is a wasteful number, since it uses less digits than its factorization.

20807201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1223970.

The product of its (nonzero) digits is 224, while the sum is 20.

The square root of 20807201 is about 4561.4910939297. The cubic root of 20807201 is about 275.0455065188.

The spelling of 20807201 in words is "twenty million, eight hundred seven thousand, two hundred one".

Divisors: 1 17 1223953 20807201