1221012112101 has 16 divisors (see below), whose sum is σ = 1647087724800. Its totient is φ = 804495633408.

The previous prime is 1221012112081. The next prime is 1221012112129. The reversal of 1221012112101 is 1012112101221.

It is a happy number.

It is not a de Polignac number, because 1221012112101 - 2³⁴ = 1203832242917 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221012112301) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2708656 + ... + 3127113.

It is an arithmetic number, because the mean of its divisors is an integer number (102942982800).

Almost surely, 2^{1221012112101} is an apocalyptic number.

It is an amenable number.

1221012112101 is a deficient number, since it is larger than the sum of its proper divisors (426075612699).

1221012112101 is an equidigital number, since it uses as much as digits as its factorization.

1221012112101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5836588.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 1221012112101 its reverse (1012112101221), we get a palindrome (2233124213322).

The spelling of 1221012112101 in words is "one trillion, two hundred twenty-one billion, twelve million, one hundred twelve thousand, one hundred one".