215750081 has 2 divisors, whose sum is σ = 215750082. Its totient is φ = 215750080.

The previous prime is 215750021. The next prime is 215750123. The reversal of 215750081 is 180057512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 206899456 + 8850625 = 14384^2 + 2975^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-215750081 is a prime.

It is a super-2 number, since 2×215750081² = 93096194903013122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (215750011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107875040 + 107875041.

It is an arithmetic number, because the mean of its divisors is an integer number (107875041).

Almost surely, 2^215750081 is an apocalyptic number.

It is an amenable number.

215750081 is a deficient number, since it is larger than the sum of its proper divisors (1).

215750081 is an equidigital number, since it uses as much as digits as its factorization.

215750081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2800, while the sum is 29.

The square root of 215750081 is about 14688.4335788402. The cubic root of 215750081 is about 599.7685042128.

The spelling of 215750081 in words is "two hundred fifteen million, seven hundred fifty thousand, eighty-one".