1221201200101 has 16 divisors (see below), whose sum is σ = 1238291808624. Its totient is φ = 1204233398784.

The previous prime is 1221201200083. The next prime is 1221201200123. The reversal of 1221201200101 is 1010021021221.

It can be written as a sum of positive squares in 8 ways, for example, as 271648397601 + 949552802500 = 521199^2 + 974450^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221201200101 - 2¹¹ = 1221201198053 is a prime.

It is a super-2 number, since 2×1221201200101² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221201207101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 122445751 + ... + 122455723.

It is an arithmetic number, because the mean of its divisors is an integer number (77393238039).

Almost surely, 2^{1221201200101} is an apocalyptic number.

It is an amenable number.

1221201200101 is a deficient number, since it is larger than the sum of its proper divisors (17090608523).

1221201200101 is a wasteful number, since it uses less digits than its factorization.

1221201200101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15960.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 1221201200101 its reverse (1010021021221), we get a palindrome (2231222221322).

The spelling of 1221201200101 in words is "one trillion, two hundred twenty-one billion, two hundred one million, two hundred thousand, one hundred one".