215392547921 has 2 divisors, whose sum is σ = 215392547922. Its totient is φ = 215392547920.

The previous prime is 215392547911. The next prime is 215392547933. The reversal of 215392547921 is 129745293512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 210814131025 + 4578416896 = 459145^2 + 67664^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-215392547921 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 215392547921.

It is not a weakly prime, because it can be changed into another prime (215392547911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107696273960 + 107696273961.

It is an arithmetic number, because the mean of its divisors is an integer number (107696273961).

Almost surely, 2^215392547921 is an apocalyptic number.

It is an amenable number.

215392547921 is a deficient number, since it is larger than the sum of its proper divisors (1).

215392547921 is an equidigital number, since it uses as much as digits as its factorization.

215392547921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1360800, while the sum is 50.

The spelling of 215392547921 in words is "two hundred fifteen billion, three hundred ninety-two million, five hundred forty-seven thousand, nine hundred twenty-one".