221510213 has 2 divisors, whose sum is σ = 221510214. Its totient is φ = 221510212.

The previous prime is 221510147. The next prime is 221510257. The reversal of 221510213 is 312015122.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 155201764 + 66308449 = 12458^2 + 8143^2 .

It is a cyclic number.

It is not a de Polignac number, because 221510213 - 2²² = 217315909 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221510191 and 221510200.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221510713) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110755106 + 110755107.

It is an arithmetic number, because the mean of its divisors is an integer number (110755107).

Almost surely, 2^221510213 is an apocalyptic number.

It is an amenable number.

221510213 is a deficient number, since it is larger than the sum of its proper divisors (1).

221510213 is an equidigital number, since it uses as much as digits as its factorization.

221510213 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 221510213 is about 14883.2191746275. The cubic root of 221510213 is about 605.0592688332.

Adding to 221510213 its reverse (312015122), we get a palindrome (533525335).

The spelling of 221510213 in words is "two hundred twenty-one million, five hundred ten thousand, two hundred thirteen".