215147281 has 2 divisors, whose sum is σ = 215147282. Its totient is φ = 215147280.

The previous prime is 215147249. The next prime is 215147321. The reversal of 215147281 is 182741512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 212897281 + 2250000 = 14591^2 + 1500^2 .

It is a cyclic number.

It is not a de Polignac number, because 215147281 - 2⁵ = 215147249 is a prime.

It is a super-2 number, since 2×215147281² = 92576705043385922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (215117281) 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, 107573640 + 107573641.

It is an arithmetic number, because the mean of its divisors is an integer number (107573641).

Almost surely, 2^215147281 is an apocalyptic number.

It is an amenable number.

215147281 is a deficient number, since it is larger than the sum of its proper divisors (1).

215147281 is an equidigital number, since it uses as much as digits as its factorization.

215147281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4480, while the sum is 31.

The square root of 215147281 is about 14667.8996792315. The cubic root of 215147281 is about 599.2094040914.

Adding to 215147281 its reverse (182741512), we get a palindrome (397888793).

The spelling of 215147281 in words is "two hundred fifteen million, one hundred forty-seven thousand, two hundred eighty-one".