215481285 has 12 divisors (see below), whose sum is σ = 373500972. Its totient is φ = 114923328.

The previous prime is 215481271. The next prime is 215481293. The reversal of 215481285 is 582184512.

215481285 is a `hidden beast` number, since 21 + 548 + 12 + 85 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 127983969 + 87497316 = 11313^2 + 9354^2 .

It is not a de Polignac number, because 215481285 - 2⁶ = 215481221 is a prime.

It is a congruent number.

It is an unprimeable number.

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 in 11 ways as a sum of consecutive naturals, for example, 2394192 + ... + 2394281.

It is an arithmetic number, because the mean of its divisors is an integer number (31125081).

Almost surely, 2^215481285 is an apocalyptic number.

It is an amenable number.

215481285 is a deficient number, since it is larger than the sum of its proper divisors (158019687).

215481285 is a wasteful number, since it uses less digits than its factorization.

215481285 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4788484 (or 4788481 counting only the distinct ones).

The product of its digits is 25600, while the sum is 36.

The square root of 215481285 is about 14679.2808066335. The cubic root of 215481285 is about 599.5193233528.

The spelling of 215481285 in words is "two hundred fifteen million, four hundred eighty-one thousand, two hundred eighty-five".