221021201 has 4 divisors (see below), whose sum is σ = 226412004. Its totient is φ = 215630400.

The previous prime is 221021197. The next prime is 221021221. The reversal of 221021201 is 102120122.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13690000 + 207331201 = 3700^2 + 14399^2 .

It is a cyclic number.

It is not a de Polignac number, because 221021201 - 2² = 221021197 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221021221) 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, 2695340 + ... + 2695421.

It is an arithmetic number, because the mean of its divisors is an integer number (56603001).

Almost surely, 2^221021201 is an apocalyptic number.

It is an amenable number.

221021201 is a deficient number, since it is larger than the sum of its proper divisors (5390803).

221021201 is an equidigital number, since it uses as much as digits as its factorization.

221021201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5390802.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 221021201 is about 14866.7817970131. The cubic root of 221021201 is about 604.6136923240.

Adding to 221021201 its reverse (102120122), we get a palindrome (323141323).

It can be divided in two parts, 22 and 1021201, that multiplied together give a palindrome (22466422).

The spelling of 221021201 in words is "two hundred twenty-one million, twenty-one thousand, two hundred one".