201312221 has 4 divisors (see below), whose sum is σ = 219613344. Its totient is φ = 183011100.

The previous prime is 201312217. The next prime is 201312257. The reversal of 201312221 is 122213102.

It is a happy number.

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.

It is a cyclic number.

It is not a de Polignac number, because 201312221 - 2² = 201312217 is a prime.

It is a super-2 number, since 2×201312221² = 81053220647905682, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 201312196 and 201312205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201312211) 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, 9150545 + ... + 9150566.

It is an arithmetic number, because the mean of its divisors is an integer number (54903336).

Almost surely, 2^201312221 is an apocalyptic number.

It is an amenable number.

201312221 is a deficient number, since it is larger than the sum of its proper divisors (18301123).

201312221 is a wasteful number, since it uses less digits than its factorization.

201312221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18301122.

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 201312221 is about 14188.4537917280. The cubic root of 201312221 is about 586.0797464341.

Adding to 201312221 its reverse (122213102), we get a palindrome (323525323).

The spelling of 201312221 in words is "two hundred one million, three hundred twelve thousand, two hundred twenty-one".