213121303102121 has 4 divisors (see below), whose sum is σ = 213164895110100. Its totient is φ = 213077711094144.

The previous prime is 213121303102087. The next prime is 213121303102139. The reversal of 213121303102121 is 121201303121312.

It is a happy number.

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 59183187549721 + 153938115552400 = 7693061^2 + 12407180^2 .

It is a cyclic number.

It is not a de Polignac number, because 213121303102121 - 2²² = 213121298907817 is a prime.

It is a super-2 number, since 2×213121303102121² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (213121303102021) 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, 21795996656 + ... + 21796006433.

It is an arithmetic number, because the mean of its divisors is an integer number (53291223777525).

Almost surely, 2^{213121303102121} is an apocalyptic number.

It is an amenable number.

213121303102121 is a deficient number, since it is larger than the sum of its proper divisors (43592007979).

213121303102121 is an equidigital number, since it uses as much as digits as its factorization.

213121303102121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43592007978.

The product of its (nonzero) digits is 432, while the sum is 23.

Adding to 213121303102121 its reverse (121201303121312), we get a palindrome (334322606223433).

The spelling of 213121303102121 in words is "two hundred thirteen trillion, one hundred twenty-one billion, three hundred three million, one hundred two thousand, one hundred twenty-one".