213531020221 has 2 divisors, whose sum is σ = 213531020222. Its totient is φ = 213531020220.

The previous prime is 213531020191. The next prime is 213531020281. The reversal of 213531020221 is 122020135312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 174519240025 + 39011780196 = 417755^2 + 197514^2 .

It is a cyclic number.

It is not a de Polignac number, because 213531020221 - 2⁷ = 213531020093 is a prime.

It is a super-2 number, since 2×213531020221² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 213531020192 and 213531020201.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213531020281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106765510110 + 106765510111.

It is an arithmetic number, because the mean of its divisors is an integer number (106765510111).

Almost surely, 2^213531020221 is an apocalyptic number.

It is an amenable number.

213531020221 is a deficient number, since it is larger than the sum of its proper divisors (1).

213531020221 is an equidigital number, since it uses as much as digits as its factorization.

213531020221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 720, while the sum is 22.

Adding to 213531020221 its reverse (122020135312), we get a palindrome (335551155533).

The spelling of 213531020221 in words is "two hundred thirteen billion, five hundred thirty-one million, twenty thousand, two hundred twenty-one".