1021212101221 has 4 divisors (see below), whose sum is σ = 1099766878252. Its totient is φ = 942657324192.

The previous prime is 1021212101177. The next prime is 1021212101269. The reversal of 1021212101221 is 1221012121201.

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 44700530625 + 976511570596 = 211425^2 + 988186^2 .

It is a cyclic number.

It is not a de Polignac number, because 1021212101221 - 2⁷ = 1021212101093 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1021212101195 and 1021212101204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021212101321) 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, 39277388496 + ... + 39277388521.

It is an arithmetic number, because the mean of its divisors is an integer number (274941719563).

Almost surely, 2^{1021212101221} is an apocalyptic number.

It is an amenable number.

1021212101221 is a deficient number, since it is larger than the sum of its proper divisors (78554777031).

1021212101221 is an equidigital number, since it uses as much as digits as its factorization.

1021212101221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78554777030.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 1021212101221 its reverse (1221012121201), we get a palindrome (2242224222422).

The spelling of 1021212101221 in words is "one trillion, twenty-one billion, two hundred twelve million, one hundred one thousand, two hundred twenty-one".