221020201 has 4 divisors (see below), whose sum is σ = 221056452. Its totient is φ = 220983952.

The previous prime is 221020199. The next prime is 221020207. The reversal of 221020201 is 102020122.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 102020122 = 2 ⋅51010061.

It can be written as a sum of positive squares in 2 ways, for example, as 151880976 + 69139225 = 12324^2 + 8315^2 .

It is a cyclic number.

It is not a de Polignac number, because 221020201 - 2¹ = 221020199 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221020207) 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, 6490 + ... + 22003.

It is an arithmetic number, because the mean of its divisors is an integer number (55264113).

Almost surely, 2^221020201 is an apocalyptic number.

It is an amenable number.

221020201 is a deficient number, since it is larger than the sum of its proper divisors (36251).

221020201 is an equidigital number, since it uses as much as digits as its factorization.

221020201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36250.

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 221020201 is about 14866.7481649485. The cubic root of 221020201 is about 604.6127804739.

Adding to 221020201 its reverse (102020122), we get a palindrome (323040323).

It can be divided in two parts, 22 and 1020201, that multiplied together give a palindrome (22444422).

The spelling of 221020201 in words is "two hundred twenty-one million, twenty thousand, two hundred one".