1231211121021 has 24 divisors (see below), whose sum is σ = 2058203047680. Its totient is φ = 694643522976.

The previous prime is 1231211120989. The next prime is 1231211121059. The reversal of 1231211121021 is 1201211121321.

It is a happy number.

1231211121021 is a `hidden beast` number, since 12 + 312 + 111 + 210 + 21 = 666.

It is not a de Polignac number, because 1231211121021 - 2⁵ = 1231211120989 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1231211120985 and 1231211121003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231211121121) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 123685110 + ... + 123695063.

It is an arithmetic number, because the mean of its divisors is an integer number (85758460320).

Almost surely, 2^{1231211121021} is an apocalyptic number.

It is an amenable number.

1231211121021 is a deficient number, since it is larger than the sum of its proper divisors (826991926659).

1231211121021 is a wasteful number, since it uses less digits than its factorization.

1231211121021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 247380265 (or 247380262 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 18.

Adding to 1231211121021 its reverse (1201211121321), we get a palindrome (2432422242342).

The spelling of 1231211121021 in words is "one trillion, two hundred thirty-one billion, two hundred eleven million, one hundred twenty-one thousand, twenty-one".