1221220343231 has 4 divisors (see below), whose sum is σ = 1395680392272. Its totient is φ = 1046760294192.

The previous prime is 1221220343201. The next prime is 1221220343269. The reversal of 1221220343231 is 1323430221221.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1221220343231 - 2¹⁴ = 1221220326847 is a prime.

It is a super-2 number, since 2×1221220343231² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1221220343231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221220343201) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 87230024510 + ... + 87230024523.

It is an arithmetic number, because the mean of its divisors is an integer number (348920098068).

Almost surely, 2^{1221220343231} is an apocalyptic number.

1221220343231 is a deficient number, since it is larger than the sum of its proper divisors (174460049041).

1221220343231 is an equidigital number, since it uses as much as digits as its factorization.

1221220343231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174460049040.

The product of its (nonzero) digits is 3456, while the sum is 26.

Adding to 1221220343231 its reverse (1323430221221), we get a palindrome (2544650564452).

The spelling of 1221220343231 in words is "one trillion, two hundred twenty-one billion, two hundred twenty million, three hundred forty-three thousand, two hundred thirty-one".