201091 has 8 divisors (see below), whose sum is σ = 222768. Its totient is φ = 180000.

The previous prime is 201073. The next prime is 201101. The reversal of 201091 is 190102.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a 5-Lehmer number, since φ(201091) divides (201091-1)⁵.

It is a cyclic number.

It is not a de Polignac number, because 201091 - 2⁹ = 200579 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 (201011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1021 + ... + 1201.

It is an arithmetic number, because the mean of its divisors is an integer number (27846).

2²⁰¹⁰⁹¹ is an apocalyptic number.

201091 is a deficient number, since it is larger than the sum of its proper divisors (21677).

201091 is a wasteful number, since it uses less digits than its factorization.

201091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 293.

The product of its (nonzero) digits is 18, while the sum is 13.

The square root of 201091 is about 448.4317116351. The cubic root of 201091 is about 58.5864987708.

Adding to 201091 its reverse (190102), we get a palindrome (391193).

It can be divided in two parts, 20 and 1091, that added together give a palindrome (1111).

The spelling of 201091 in words is "two hundred one thousand, ninety-one".