1211023130021 has 4 divisors (see below), whose sum is σ = 1211335172844. Its totient is φ = 1210711087200.

The previous prime is 1211023129999. The next prime is 1211023130069. The reversal of 1211023130021 is 1200313201121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 398836456225 + 812186673796 = 631535^2 + 901214^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211023130021 - 2¹⁸ = 1211022867877 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211023130071) 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, 156015590 + ... + 156023351.

It is an arithmetic number, because the mean of its divisors is an integer number (302833793211).

Almost surely, 2^{1211023130021} is an apocalyptic number.

It is an amenable number.

1211023130021 is a deficient number, since it is larger than the sum of its proper divisors (312042823).

1211023130021 is an equidigital number, since it uses as much as digits as its factorization.

1211023130021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 312042822.

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 1211023130021 its reverse (1200313201121), we get a palindrome (2411336331142).

The spelling of 1211023130021 in words is "one trillion, two hundred eleven billion, twenty-three million, one hundred thirty thousand, twenty-one".