201221131 has 4 divisors (see below), whose sum is σ = 201270232. Its totient is φ = 201172032.

The previous prime is 201221113. The next prime is 201221143. The reversal of 201221131 is 131122102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 131122102 = 2 ⋅65561051.

It is a cyclic number.

It is not a de Polignac number, because 201221131 - 2⁵ = 201221099 is a prime.

It is a super-2 number, since 2×201221131² = 80979887121838322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (201221101) 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, 17781 + ... + 26806.

It is an arithmetic number, because the mean of its divisors is an integer number (50317558).

Almost surely, 2^201221131 is an apocalyptic number.

201221131 is a deficient number, since it is larger than the sum of its proper divisors (49101).

201221131 is an equidigital number, since it uses as much as digits as its factorization.

201221131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49100.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 201221131 is about 14185.2434240657. The cubic root of 201221131 is about 585.9913364047.

Adding to 201221131 its reverse (131122102), we get a palindrome (332343233).

The spelling of 201221131 in words is "two hundred one million, two hundred twenty-one thousand, one hundred thirty-one".