215845081 has 2 divisors, whose sum is σ = 215845082. Its totient is φ = 215845080.

The previous prime is 215845061. The next prime is 215845093. The reversal of 215845081 is 180548512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 215825481 + 19600 = 14691^2 + 140^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-215845081 is a prime.

It is a super-2 number, since 2×215845081² = 93178197983793122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (215845031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107922540 + 107922541.

It is an arithmetic number, because the mean of its divisors is an integer number (107922541).

Almost surely, 2^215845081 is an apocalyptic number.

It is an amenable number.

215845081 is a deficient number, since it is larger than the sum of its proper divisors (1).

215845081 is an equidigital number, since it uses as much as digits as its factorization.

215845081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12800, while the sum is 34.

The square root of 215845081 is about 14691.6670599357. The cubic root of 215845081 is about 599.8565221744.

The spelling of 215845081 in words is "two hundred fifteen million, eight hundred forty-five thousand, eighty-one".