1221100110121 has 6 divisors (see below), whose sum is σ = 1264658973422. Its totient is φ = 1178993208960.

The previous prime is 1221100110103. The next prime is 1221100110127. The reversal of 1221100110121 is 1210110011221.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 11276103721 + 1209824006400 = 106189^2 + 1099920^2 .

It is not a de Polignac number, because 1221100110121 - 2²³ = 1221091721513 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1221100110127) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 725980200 + ... + 725981881.

Almost surely, 2^{1221100110121} is an apocalyptic number.

It is an amenable number.

1221100110121 is a deficient number, since it is larger than the sum of its proper divisors (43558863301).

1221100110121 is an equidigital number, since it uses as much as digits as its factorization.

1221100110121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1451962139 (or 1451962110 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 1221100110121 its reverse (1210110011221), we get a palindrome (2431210121342).

The spelling of 1221100110121 in words is "one trillion, two hundred twenty-one billion, one hundred million, one hundred ten thousand, one hundred twenty-one".