1221223023421 has 2 divisors, whose sum is σ = 1221223023422. Its totient is φ = 1221223023420.

The previous prime is 1221223023413. The next prime is 1221223023443. The reversal of 1221223023421 is 1243203221221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 722100555225 + 499122468196 = 849765^2 + 706486^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221223023421 - 2³ = 1221223023413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221223023481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610611511710 + 610611511711.

It is an arithmetic number, because the mean of its divisors is an integer number (610611511711).

Almost surely, 2^{1221223023421} is an apocalyptic number.

It is an amenable number.

1221223023421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221223023421 is an equidigital number, since it uses as much as digits as its factorization.

1221223023421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2304, while the sum is 25.

Adding to 1221223023421 its reverse (1243203221221), we get a palindrome (2464426244642).

The spelling of 1221223023421 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-three million, twenty-three thousand, four hundred twenty-one".