It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 10911 = 3 ⋅3637.
It is a D-number.
It is a Duffinian number.
It is a plaindrome in base 13.
It is a congruent number.
211901 is an apocalyptic number.
It is an amenable number.
11901 is an equidigital number, since it uses as much as digits as its factorization.
11901 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 3970.
The square root of 11901 is about 109.0917045426. The cubic root of 11901 is about 22.8311516318.
Subtracting from 11901 its reverse (10911), we obtain a triangular number (990 = T44).
The spelling of 11901 in words is "eleven thousand, nine hundred one".