201881 has 2 divisors, whose sum is σ = 201882. Its totient is φ = 201880.

The previous prime is 201847. The next prime is 201889. The reversal of 201881 is 188102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 193600 + 8281 = 440^2 + 91^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-201881 is a prime.

It is a super-2 number, since 2×201881² = 81511876322, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (201889) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100940 + 100941.

It is an arithmetic number, because the mean of its divisors is an integer number (100941).

2²⁰¹⁸⁸¹ is an apocalyptic number.

It is an amenable number.

201881 is a deficient number, since it is larger than the sum of its proper divisors (1).

201881 is an equidigital number, since it uses as much as digits as its factorization.

201881 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 128, while the sum is 20.

The square root of 201881 is about 449.3116958193. The cubic root of 201881 is about 58.6631189028.

Adding to 201881 its reverse (188102), we get a palindrome (389983).

The spelling of 201881 in words is "two hundred one thousand, eight hundred eighty-one".