201645 has 12 divisors (see below), whose sum is σ = 349596. Its totient is φ = 107520.

The previous prime is 201629. The next prime is 201653. The reversal of 201645 is 546102.

It is a happy number.

201645 is a `hidden beast` number, since 20 + 1 + 645 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 116964 + 84681 = 342^2 + 291^2 .

It is not a de Polignac number, because 201645 - 2⁴ = 201629 is a prime.

It is a super-3 number, since 3×201645³ = 24597084199233375, which contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2196 + ... + 2285.

It is an arithmetic number, because the mean of its divisors is an integer number (29133).

2²⁰¹⁶⁴⁵ is an apocalyptic number.

It is an amenable number.

201645 is a deficient number, since it is larger than the sum of its proper divisors (147951).

201645 is a wasteful number, since it uses less digits than its factorization.

201645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4492 (or 4489 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 201645 is about 449.0489950996. The cubic root of 201645 is about 58.6402508199.

Adding to 201645 its reverse (546102), we get a palindrome (747747).

The spelling of 201645 in words is "two hundred one thousand, six hundred forty-five".