1212212021221 has 8 divisors (see below), whose sum is σ = 1228491495000. Its totient is φ = 1195991639040.

The previous prime is 1212212021203. The next prime is 1212212021233. The reversal of 1212212021221 is 1221202122121.

It can be written as a sum of positive squares in 4 ways, for example, as 76945212100 + 1135266809121 = 277390^2 + 1065489^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1212212021221 - 2¹⁹ = 1212211496933 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212212021521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14731596 + ... + 14813653.

It is an arithmetic number, because the mean of its divisors is an integer number (153561436875).

Almost surely, 2^{1212212021221} is an apocalyptic number.

It is an amenable number.

1212212021221 is a deficient number, since it is larger than the sum of its proper divisors (16279473779).

1212212021221 is an equidigital number, since it uses as much as digits as its factorization.

1212212021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29545799.

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

Adding to 1212212021221 its reverse (1221202122121), we get a palindrome (2433414143342).

The spelling of 1212212021221 in words is "one trillion, two hundred twelve billion, two hundred twelve million, twenty-one thousand, two hundred twenty-one".