215510343345581 has 2 divisors, whose sum is σ = 215510343345582. Its totient is φ = 215510343345580.

The previous prime is 215510343345569. The next prime is 215510343345607. The reversal of 215510343345581 is 185543343015512.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 111962745750025 + 103547597595556 = 10581245^2 + 10175834^2 .

It is a cyclic number.

It is not a de Polignac number, because 215510343345581 - 2³⁴ = 215493163476397 is a prime.

It is a super-2 number, since 2×215510343345581² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (215510343345181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107755171672790 + 107755171672791.

It is an arithmetic number, because the mean of its divisors is an integer number (107755171672791).

Almost surely, 2^{215510343345581} is an apocalyptic number.

It is an amenable number.

215510343345581 is a deficient number, since it is larger than the sum of its proper divisors (1).

215510343345581 is an equidigital number, since it uses as much as digits as its factorization.

215510343345581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4320000, while the sum is 50.

The spelling of 215510343345581 in words is "two hundred fifteen trillion, five hundred ten billion, three hundred forty-three million, three hundred forty-five thousand, five hundred eighty-one".