215715611261 has 2 divisors, whose sum is σ = 215715611262. Its totient is φ = 215715611260.

The previous prime is 215715611239. The next prime is 215715611297. The reversal of 215715611261 is 162116517512.

215715611261 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 209475559225 + 6240052036 = 457685^2 + 78994^2 .

It is a cyclic number.

It is not a de Polignac number, because 215715611261 - 2⁶ = 215715611197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (215715011261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107857805630 + 107857805631.

It is an arithmetic number, because the mean of its divisors is an integer number (107857805631).

Almost surely, 2^215715611261 is an apocalyptic number.

It is an amenable number.

215715611261 is a deficient number, since it is larger than the sum of its proper divisors (1).

215715611261 is an equidigital number, since it uses as much as digits as its factorization.

215715611261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25200, while the sum is 38.

The spelling of 215715611261 in words is "two hundred fifteen billion, seven hundred fifteen million, six hundred eleven thousand, two hundred sixty-one".