1232121221 has 2 divisors, whose sum is σ = 1232121222. Its totient is φ = 1232121220.

The previous prime is 1232121211. The next prime is 1232121227. The reversal of 1232121221 is 1221212321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1189284196 + 42837025 = 34486^2 + 6545^2 .

It is a cyclic number.

It is not a de Polignac number, because 1232121221 - 2¹⁸ = 1231859077 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1232121221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1232121227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 616060610 + 616060611.

It is an arithmetic number, because the mean of its divisors is an integer number (616060611).

Almost surely, 2^1232121221 is an apocalyptic number.

It is an amenable number.

1232121221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1232121221 is an equidigital number, since it uses as much as digits as its factorization.

1232121221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 96, while the sum is 17.

The square root of 1232121221 is about 35101.5843089739. The cubic root of 1232121221 is about 1072.0568410888.

Adding to 1232121221 its reverse (1221212321), we get a palindrome (2453333542).

The spelling of 1232121221 in words is "one billion, two hundred thirty-two million, one hundred twenty-one thousand, two hundred twenty-one".