215539081 has 2 divisors, whose sum is σ = 215539082. Its totient is φ = 215539080.

The previous prime is 215539069. The next prime is 215539111. The reversal of 215539081 is 180935512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 187279225 + 28259856 = 13685^2 + 5316^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-215539081 is a prime.

It is a super-2 number, since 2×215539081² = 92914190876649122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (215531081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107769540 + 107769541.

It is an arithmetic number, because the mean of its divisors is an integer number (107769541).

Almost surely, 2^215539081 is an apocalyptic number.

It is an amenable number.

215539081 is a deficient number, since it is larger than the sum of its proper divisors (1).

215539081 is an equidigital number, since it uses as much as digits as its factorization.

215539081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10800, while the sum is 34.

The square root of 215539081 is about 14681.2492997020. The cubic root of 215539081 is about 599.5729192236.

The spelling of 215539081 in words is "two hundred fifteen million, five hundred thirty-nine thousand, eighty-one".