213121013321 has 2 divisors, whose sum is σ = 213121013322. Its totient is φ = 213121013320.

The previous prime is 213121013317. The next prime is 213121013327. The reversal of 213121013321 is 123310121312.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 169245846025 + 43875167296 = 411395^2 + 209464^2 .

It is a cyclic number.

It is not a de Polignac number, because 213121013321 - 2² = 213121013317 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 213121013293 and 213121013302.

It is not a weakly prime, because it can be changed into another prime (213121013327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106560506660 + 106560506661.

It is an arithmetic number, because the mean of its divisors is an integer number (106560506661).

Almost surely, 2^213121013321 is an apocalyptic number.

It is an amenable number.

213121013321 is a deficient number, since it is larger than the sum of its proper divisors (1).

213121013321 is an equidigital number, since it uses as much as digits as its factorization.

213121013321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 20.

Adding to 213121013321 its reverse (123310121312), we get a palindrome (336431134633).

The spelling of 213121013321 in words is "two hundred thirteen billion, one hundred twenty-one million, thirteen thousand, three hundred twenty-one".