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213445 = 542689
BaseRepresentation
bin110100000111000101
3101211210101
4310013011
523312240
64324101
71546201
oct640705
9354711
10213445
11136401
12a3631
13761cb
1457b01
154339a
hex341c5

213445 has 4 divisors (see below), whose sum is σ = 256140. Its totient is φ = 170752.

The previous prime is 213407. The next prime is 213449. The reversal of 213445 is 544312.

It is a Cunningham number, because it is equal to 4622+1.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 77284 + 136161 = 278^2 + 369^2 .

It is a cyclic number.

It is not a de Polignac number, because 213445 - 213 = 205253 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213449) 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, 21340 + ... + 21349.

It is an arithmetic number, because the mean of its divisors is an integer number (64035).

2213445 is an apocalyptic number.

It is an amenable number.

213445 is a deficient number, since it is larger than the sum of its proper divisors (42695).

213445 is an equidigital number, since it uses as much as digits as its factorization.

213445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42694.

The product of its digits is 480, while the sum is 19.

The square root of 213445 is about 462.0010822498. The cubic root of 213445 is about 59.7624869591.

Adding to 213445 its reverse (544312), we get a palindrome (757757).

The spelling of 213445 in words is "two hundred thirteen thousand, four hundred forty-five".

Divisors: 1 5 42689 213445