1221010100101 has 16 divisors (see below), whose sum is σ = 1428571909440. Its totient is φ = 1031746360320.

The previous prime is 1221010100083. The next prime is 1221010100143. The reversal of 1221010100101 is 1010010101221.

It is a cyclic number.

It is not a de Polignac number, because 1221010100101 - 2³⁷ = 1083571146629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221010110101) 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, 55103580 + ... + 55125733.

It is an arithmetic number, because the mean of its divisors is an integer number (89285744340).

Almost surely, 2^{1221010100101} is an apocalyptic number.

1221010100101 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1221010100101 is a deficient number, since it is larger than the sum of its proper divisors (207561809339).

1221010100101 is a wasteful number, since it uses less digits than its factorization.

1221010100101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110229396.

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

Adding to 1221010100101 its reverse (1010010101221), we get a palindrome (2231020201322).

The spelling of 1221010100101 in words is "one trillion, two hundred twenty-one billion, ten million, one hundred thousand, one hundred one".