1221000010101 has 12 divisors (see below), whose sum is σ = 1811333348812. Its totient is φ = 792000006336.

The previous prime is 1221000010099. The next prime is 1221000010127. The reversal of 1221000010101 is 1010100001221.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 535639551876 + 685360458225 = 731874^2 + 827865^2 .

It is not a de Polignac number, because 1221000010101 - 2¹ = 1221000010099 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221000010001) 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 11 ways as a sum of consecutive naturals, for example, 1833333016 + ... + 1833333681.

Almost surely, 2^{1221000010101} is an apocalyptic number.

It is an amenable number.

1221000010101 is a deficient number, since it is larger than the sum of its proper divisors (590333338711).

1221000010101 is a wasteful number, since it uses less digits than its factorization.

1221000010101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3666666740 (or 3666666737 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 1221000010101 its reverse (1010100001221), we get a palindrome (2231100011322).

The spelling of 1221000010101 in words is "one trillion, two hundred twenty-one billion, ten thousand, one hundred one".