212012561521 has 2 divisors, whose sum is σ = 212012561522. Its totient is φ = 212012561520.

The previous prime is 212012561503. The next prime is 212012561561. The reversal of 212012561521 is 125165210212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 204088001121 + 7924560400 = 451761^2 + 89020^2 .

It is a cyclic number.

It is not a de Polignac number, because 212012561521 - 2²⁵ = 211979007089 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 212012561521.

It is not a weakly prime, because it can be changed into another prime (212012561561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106006280760 + 106006280761.

It is an arithmetic number, because the mean of its divisors is an integer number (106006280761).

Almost surely, 2^212012561521 is an apocalyptic number.

It is an amenable number.

212012561521 is a deficient number, since it is larger than the sum of its proper divisors (1).

212012561521 is an equidigital number, since it uses as much as digits as its factorization.

212012561521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2400, while the sum is 28.

Adding to 212012561521 its reverse (125165210212), we get a palindrome (337177771733).

The spelling of 212012561521 in words is "two hundred twelve billion, twelve million, five hundred sixty-one thousand, five hundred twenty-one".