1211001021121 has 4 divisors (see below), whose sum is σ = 1212053151744. Its totient is φ = 1209948890500.

The previous prime is 1211001021089. The next prime is 1211001021127. The reversal of 1211001021121 is 1211201001121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1211001021121 - 2⁵ = 1211001021089 is a prime.

It is a super-2 number, since 2×1211001021121² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1211001021127) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 526063585 + ... + 526065886.

It is an arithmetic number, because the mean of its divisors is an integer number (303013287936).

Almost surely, 2^{1211001021121} is an apocalyptic number.

It is an amenable number.

1211001021121 is a deficient number, since it is larger than the sum of its proper divisors (1052130623).

1211001021121 is a wasteful number, since it uses less digits than its factorization.

1211001021121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1052130622.

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

Adding to 1211001021121 its reverse (1211201001121), we get a palindrome (2422202022242).

The spelling of 1211001021121 in words is "one trillion, two hundred eleven billion, one million, twenty-one thousand, one hundred twenty-one".