1212221212021 has 4 divisors (see below), whose sum is σ = 1254021943500. Its totient is φ = 1170420480544.

The previous prime is 1212221211997. The next prime is 1212221212039. The reversal of 1212221212021 is 1202121222121.

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

It can be written as a sum of positive squares in 2 ways, for example, as 594363902500 + 617857309521 = 770950^2 + 786039^2 .

It is a cyclic number.

It is not a de Polignac number, because 1212221212021 - 2¹¹ = 1212221209973 is a prime.

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 1212221212021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212221212421) 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, 20900365696 + ... + 20900365753.

It is an arithmetic number, because the mean of its divisors is an integer number (313505485875).

Almost surely, 2^{1212221212021} is an apocalyptic number.

It is an amenable number.

1212221212021 is a deficient number, since it is larger than the sum of its proper divisors (41800731479).

1212221212021 is an equidigital number, since it uses as much as digits as its factorization.

1212221212021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41800731478.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 1212221212021 its reverse (1202121222121), we get a palindrome (2414342434142).

The spelling of 1212221212021 in words is "one trillion, two hundred twelve billion, two hundred twenty-one million, two hundred twelve thousand, twenty-one".