1221221423 has 2 divisors, whose sum is σ = 1221221424. Its totient is φ = 1221221422.

The previous prime is 1221221411. The next prime is 1221221437. The reversal of 1221221423 is 3241221221.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1221221423 - 2²⁰ = 1220172847 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1221221395 and 1221221404.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221221473) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610610711 + 610610712.

It is an arithmetic number, because the mean of its divisors is an integer number (610610712).

Almost surely, 2^1221221423 is an apocalyptic number.

1221221423 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221221423 is an equidigital number, since it uses as much as digits as its factorization.

1221221423 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 384, while the sum is 20.

The square root of 1221221423 is about 34945.9786384643. The cubic root of 1221221423 is about 1068.8862032311.

Adding to 1221221423 its reverse (3241221221), we get a palindrome (4462442644).

The spelling of 1221221423 in words is "one billion, two hundred twenty-one million, two hundred twenty-one thousand, four hundred twenty-three".