1221100100101 has 32 divisors (see below), whose sum is σ = 1495493618688. Its totient is φ = 973224806400.

The previous prime is 1221100100093. The next prime is 1221100100107. The reversal of 1221100100101 is 1010010011221.

It is not a de Polignac number, because 1221100100101 - 2³ = 1221100100093 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221100100107) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5455081 + ... + 5674513.

It is an arithmetic number, because the mean of its divisors is an integer number (46734175584).

Almost surely, 2^{1221100100101} is an apocalyptic number.

It is an amenable number.

1221100100101 is a deficient number, since it is larger than the sum of its proper divisors (274393518587).

1221100100101 is a wasteful number, since it uses less digits than its factorization.

1221100100101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220021.

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 1221100100101 its reverse (1010010011221), we get a palindrome (2231110111322).

The spelling of 1221100100101 in words is "one trillion, two hundred twenty-one billion, one hundred million, one hundred thousand, one hundred one".