221220101 has 2 divisors, whose sum is σ = 221220102. Its totient is φ = 221220100.

The previous prime is 221220089. The next prime is 221220107. The reversal of 221220101 is 101022122.

It is a happy number.

221220101 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 185232100 + 35988001 = 13610^2 + 5999^2 .

It is a cyclic number.

It is not a de Polignac number, because 221220101 - 2⁶ = 221220037 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221220107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110610050 + 110610051.

It is an arithmetic number, because the mean of its divisors is an integer number (110610051).

Almost surely, 2^221220101 is an apocalyptic number.

It is an amenable number.

221220101 is a deficient number, since it is larger than the sum of its proper divisors (1).

221220101 is an equidigital number, since it uses as much as digits as its factorization.

221220101 is an evil number, because the sum of its binary digits is even.

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

The square root of 221220101 is about 14873.4697027963. The cubic root of 221220101 is about 604.7950046551.

Adding to 221220101 its reverse (101022122), we get a palindrome (322242223).

The spelling of 221220101 in words is "two hundred twenty-one million, two hundred twenty thousand, one hundred one".