201550221 has 8 divisors (see below), whose sum is σ = 298592960. Its totient is φ = 134366796.

The previous prime is 201550213. The next prime is 201550243. The reversal of 201550221 is 122055102.

It is not a de Polignac number, because 201550221 - 2³ = 201550213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 201550194 and 201550203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201550021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3732385 + ... + 3732438.

It is an arithmetic number, because the mean of its divisors is an integer number (37324120).

Almost surely, 2^201550221 is an apocalyptic number.

It is an amenable number.

201550221 is a deficient number, since it is larger than the sum of its proper divisors (97042739).

201550221 is an equidigital number, since it uses as much as digits as its factorization.

201550221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7464832 (or 7464826 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

The square root of 201550221 is about 14196.8384156473. The cubic root of 201550221 is about 586.3106184032.

The spelling of 201550221 in words is "two hundred one million, five hundred fifty thousand, two hundred twenty-one".