1221320123213 has 16 divisors (see below), whose sum is σ = 1305351132480. Its totient is φ = 1138645107456.

The previous prime is 1221320123171. The next prime is 1221320123393. The reversal of 1221320123213 is 3123210231221.

It is a de Polignac number, because none of the positive numbers 2^k-1221320123213 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221320128213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38115683 + ... + 38147711.

It is an arithmetic number, because the mean of its divisors is an integer number (81584445780).

Almost surely, 2^{1221320123213} is an apocalyptic number.

It is an amenable number.

1221320123213 is a deficient number, since it is larger than the sum of its proper divisors (84031009267).

1221320123213 is a wasteful number, since it uses less digits than its factorization.

1221320123213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53116.

The product of its (nonzero) digits is 864, while the sum is 23.

Adding to 1221320123213 its reverse (3123210231221), we get a palindrome (4344530354434).

The spelling of 1221320123213 in words is "one trillion, two hundred twenty-one billion, three hundred twenty million, one hundred twenty-three thousand, two hundred thirteen".