1220100221 has 2 divisors, whose sum is σ = 1220100222. Its totient is φ = 1220100220.

The previous prime is 1220100187. The next prime is 1220100269. The reversal of 1220100221 is 1220010221.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 777628996 + 442471225 = 27886^2 + 21035^2 .

It is an emirp because it is prime and its reverse (1220010221) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1220100221 - 2⁶ = 1220100157 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1220106221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610050110 + 610050111.

It is an arithmetic number, because the mean of its divisors is an integer number (610050111).

Almost surely, 2^1220100221 is an apocalyptic number.

It is an amenable number.

1220100221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1220100221 is an equidigital number, since it uses as much as digits as its factorization.

1220100221 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 1220100221 is about 34929.9330231250. The cubic root of 1220100221 is about 1068.5589886696.

Adding to 1220100221 its reverse (1220010221), we get a palindrome (2440110442).

Subtracting from 1220100221 its reverse (1220010221), we obtain a square (90000 = 300²).

The spelling of 1220100221 in words is "one billion, two hundred twenty million, one hundred thousand, two hundred twenty-one".