215312171 has 2 divisors, whose sum is σ = 215312172. Its totient is φ = 215312170.

The previous prime is 215312159. The next prime is 215312183. The reversal of 215312171 is 171213512.

It is a balanced prime because it is at equal distance from previous prime (215312159) and next prime (215312183).

It is a cyclic number.

It is not a de Polignac number, because 215312171 - 2¹⁸ = 215050027 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (215314171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107656085 + 107656086.

It is an arithmetic number, because the mean of its divisors is an integer number (107656086).

Almost surely, 2^215312171 is an apocalyptic number.

215312171 is a deficient number, since it is larger than the sum of its proper divisors (1).

215312171 is an equidigital number, since it uses as much as digits as its factorization.

215312171 is an evil number, because the sum of its binary digits is even.

The product of its digits is 420, while the sum is 23.

The square root of 215312171 is about 14673.5193801623. The cubic root of 215312171 is about 599.3624440737.

Adding to 215312171 its reverse (171213512), we get a palindrome (386525683).

The spelling of 215312171 in words is "two hundred fifteen million, three hundred twelve thousand, one hundred seventy-one".