1212221112021 has 28 divisors (see below), whose sum is σ = 1913158169920. Its totient is φ = 765613325160.

The previous prime is 1212221112017. The next prime is 1212221112031. The reversal of 1212221112021 is 1202111222121.

It is not a de Polignac number, because 1212221112021 - 2² = 1212221112017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1212221111985 and 1212221112003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212221112031) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 43745485 + ... + 43773186.

Almost surely, 2^{1212221112021} is an apocalyptic number.

It is an amenable number.

1212221112021 is a deficient number, since it is larger than the sum of its proper divisors (700937057899).

1212221112021 is an frugal number, since it uses more digits than its factorization.

1212221112021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87518708 (or 87518693 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 1212221112021 its reverse (1202111222121), we get a palindrome (2414332334142).

The spelling of 1212221112021 in words is "one trillion, two hundred twelve billion, two hundred twenty-one million, one hundred twelve thousand, twenty-one".