1221213020311 has 4 divisors (see below), whose sum is σ = 1229409081000. Its totient is φ = 1213016959624.

The previous prime is 1221213020213. The next prime is 1221213020347. The reversal of 1221213020311 is 1130203121221.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221213020311 is a prime.

It is a super-2 number, since 2×1221213020311² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221213020351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4098030121 + ... + 4098030418.

It is an arithmetic number, because the mean of its divisors is an integer number (307352270250).

Almost surely, 2^{1221213020311} is an apocalyptic number.

1221213020311 is a deficient number, since it is larger than the sum of its proper divisors (8196060689).

1221213020311 is an equidigital number, since it uses as much as digits as its factorization.

1221213020311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8196060688.

The product of its (nonzero) digits is 144, while the sum is 19.

Adding to 1221213020311 its reverse (1130203121221), we get a palindrome (2351416141532).

The spelling of 1221213020311 in words is "one trillion, two hundred twenty-one billion, two hundred thirteen million, twenty thousand, three hundred eleven".