221210000521 has 2 divisors, whose sum is σ = 221210000522. Its totient is φ = 221210000520.

The previous prime is 221210000513. The next prime is 221210000527. The reversal of 221210000521 is 125000012122.

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., 142686752121 + 78523248400 = 377739^2 + 280220^2 .

It is a cyclic number.

It is not a de Polignac number, because 221210000521 - 2³ = 221210000513 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221210000495 and 221210000504.

It is not a weakly prime, because it can be changed into another prime (221210000527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110605000260 + 110605000261.

It is an arithmetic number, because the mean of its divisors is an integer number (110605000261).

Almost surely, 2^221210000521 is an apocalyptic number.

It is an amenable number.

221210000521 is a deficient number, since it is larger than the sum of its proper divisors (1).

221210000521 is an equidigital number, since it uses as much as digits as its factorization.

221210000521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 80, while the sum is 16.

Adding to 221210000521 its reverse (125000012122), we get a palindrome (346210012643).

The spelling of 221210000521 in words is "two hundred twenty-one billion, two hundred ten million, five hundred twenty-one", and thus it is an aban number.