1221212222101 has 12 divisors (see below), whose sum is σ = 1310714676000. Its totient is φ = 1137328757928.

The previous prime is 1221212221981. The next prime is 1221212222117. The reversal of 1221212222101 is 1012222121221.

It is not a de Polignac number, because 1221212222101 - 2¹⁹ = 1221211697813 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221212222201) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28647001 + ... + 28689598.

It is an arithmetic number, because the mean of its divisors is an integer number (109226223000).

Almost surely, 2^{1221212222101} is an apocalyptic number.

It is an amenable number.

1221212222101 is a deficient number, since it is larger than the sum of its proper divisors (89502453899).

1221212222101 is an equidigital number, since it uses as much as digits as its factorization.

1221212222101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57336696 (or 57336677 counting only the distinct ones).

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

Adding to 1221212222101 its reverse (1012222121221), we get a palindrome (2233434343322).

The spelling of 1221212222101 in words is "one trillion, two hundred twenty-one billion, two hundred twelve million, two hundred twenty-two thousand, one hundred one".