2121021211021 has 4 divisors (see below), whose sum is σ = 2194159873500. Its totient is φ = 2047882548544.

The previous prime is 2121021210989. The next prime is 2121021211039. The reversal of 2121021211021 is 1201121201212.

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 1599428149225 + 521593061796 = 1264685^2 + 722214^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121021211021 - 2⁵ = 2121021210989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2121021210986 and 2121021211004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121021221021) 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, 36569331196 + ... + 36569331253.

It is an arithmetic number, because the mean of its divisors is an integer number (548539968375).

Almost surely, 2^{2121021211021} is an apocalyptic number.

It is an amenable number.

2121021211021 is a deficient number, since it is larger than the sum of its proper divisors (73138662479).

2121021211021 is an equidigital number, since it uses as much as digits as its factorization.

2121021211021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73138662478.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 2121021211021 its reverse (1201121201212), we get a palindrome (3322142412233).

The spelling of 2121021211021 in words is "two trillion, one hundred twenty-one billion, twenty-one million, two hundred eleven thousand, twenty-one".