1210001220121 has 12 divisors (see below), whose sum is σ = 1243761922620. Its totient is φ = 1176456600320.

The previous prime is 1210001220107. The next prime is 1210001220133. The reversal of 1210001220121 is 1210221000121.

It can be written as a sum of positive squares in 6 ways, for example, as 6669008896 + 1203332211225 = 81664^2 + 1096965^2 .

It is not a de Polignac number, because 1210001220121 - 2⁵ = 1210001220089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1210001220821) 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, 3347925 + ... + 3691693.

It is an arithmetic number, because the mean of its divisors is an integer number (103646826885).

Almost surely, 2^{1210001220121} is an apocalyptic number.

It is an amenable number.

1210001220121 is a deficient number, since it is larger than the sum of its proper divisors (33760702499).

1210001220121 is an frugal number, since it uses more digits than its factorization.

1210001220121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 344396 (or 344103 counting only the distinct ones).

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

Adding to 1210001220121 its reverse (1210221000121), we get a palindrome (2420222220242).

The spelling of 1210001220121 in words is "one trillion, two hundred ten billion, one million, two hundred twenty thousand, one hundred twenty-one".