220212121 has 2 divisors, whose sum is σ = 220212122. Its totient is φ = 220212120.

The previous prime is 220212079. The next prime is 220212151. The reversal of 220212121 is 121212022.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 219365721 + 846400 = 14811^2 + 920^2 .

It is a cyclic number.

It is not a de Polignac number, because 220212121 - 2¹⁷ = 220081049 is a prime.

It is not a weakly prime, because it can be changed into another prime (220212151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110106060 + 110106061.

It is an arithmetic number, because the mean of its divisors is an integer number (110106061).

Almost surely, 2^220212121 is an apocalyptic number.

It is an amenable number.

220212121 is a deficient number, since it is larger than the sum of its proper divisors (1).

220212121 is an equidigital number, since it uses as much as digits as its factorization.

220212121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 220212121 is about 14839.5458488459. The cubic root of 220212121 is about 603.8750317090.

Adding to 220212121 its reverse (121212022), we get a palindrome (341424143).

Subtracting from 220212121 its reverse (121212022), we obtain a palindrome (99000099).

It can be divided in two parts, 22021 and 2121, that added together give a palindrome (24142).

The spelling of 220212121 in words is "two hundred twenty million, two hundred twelve thousand, one hundred twenty-one".