1221012101221 has 6 divisors (see below), whose sum is σ = 1342104210566. Its totient is φ = 1110011001000.

The previous prime is 1221012101213. The next prime is 1221012101291.

1221012101221 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in only one way, i.e., 1088234944225 + 132777156996 = 1043185^2 + 364386^2 .

It is not a de Polignac number, because 1221012101221 - 2³ = 1221012101213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221012101195 and 1221012101204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221012101291) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5045504430 + ... + 5045504671.

Almost surely, 2^{1221012101221} is an apocalyptic number.

1221012101221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1221012101221 is a deficient number, since it is larger than the sum of its proper divisors (121092109345).

1221012101221 is a wasteful number, since it uses less digits than its factorization.

1221012101221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10091009123 (or 10091009112 counting only the distinct ones).

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

The spelling of 1221012101221 in words is "one trillion, two hundred twenty-one billion, twelve million, one hundred one thousand, two hundred twenty-one".