1221012021213 has 24 divisors (see below), whose sum is σ = 1764715754880. Its totient is φ = 813532019040.

The previous prime is 1221012021211. The next prime is 1221012021247. The reversal of 1221012021213 is 3121202101221.

It is not a de Polignac number, because 1221012021213 - 2¹ = 1221012021211 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221012021211) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 218386048 + ... + 218391638.

It is an arithmetic number, because the mean of its divisors is an integer number (73529823120).

Almost surely, 2^{1221012021213} is an apocalyptic number.

It is an amenable number.

1221012021213 is a deficient number, since it is larger than the sum of its proper divisors (543703733667).

1221012021213 is a wasteful number, since it uses less digits than its factorization.

1221012021213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15449 (or 15446 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

Adding to 1221012021213 its reverse (3121202101221), we get a palindrome (4342214122434).

The spelling of 1221012021213 in words is "one trillion, two hundred twenty-one billion, twelve million, twenty-one thousand, two hundred thirteen".