213520121 has 2 divisors, whose sum is σ = 213520122. Its totient is φ = 213520120.

The previous prime is 213520091. The next prime is 213520159. The reversal of 213520121 is 121025312.

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., 145540096 + 67980025 = 12064^2 + 8245^2 .

It is a cyclic number.

It is not a de Polignac number, because 213520121 - 2¹⁴ = 213503737 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 213520121.

It is not a weakly prime, because it can be changed into another prime (213520421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106760060 + 106760061.

It is an arithmetic number, because the mean of its divisors is an integer number (106760061).

Almost surely, 2^213520121 is an apocalyptic number.

It is an amenable number.

213520121 is a deficient number, since it is larger than the sum of its proper divisors (1).

213520121 is an equidigital number, since it uses as much as digits as its factorization.

213520121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 213520121 is about 14612.3277064265. The cubic root of 213520121 is about 597.6949718224.

Adding to 213520121 its reverse (121025312), we get a palindrome (334545433).

The spelling of 213520121 in words is "two hundred thirteen million, five hundred twenty thousand, one hundred twenty-one".