215531087 has 2 divisors, whose sum is σ = 215531088. Its totient is φ = 215531086.

The previous prime is 215531081. The next prime is 215531089. The reversal of 215531087 is 780135512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 215531087 - 2⁶ = 215531023 is a prime.

Together with 215531089, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

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

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107765543 + 107765544.

It is an arithmetic number, because the mean of its divisors is an integer number (107765544).

Almost surely, 2^215531087 is an apocalyptic number.

215531087 is a deficient number, since it is larger than the sum of its proper divisors (1).

215531087 is an equidigital number, since it uses as much as digits as its factorization.

215531087 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8400, while the sum is 32.

The square root of 215531087 is about 14680.9770451425. The cubic root of 215531087 is about 599.5655067316.

Adding to 215531087 its reverse (780135512), we get a palindrome (995666599).

The spelling of 215531087 in words is "two hundred fifteen million, five hundred thirty-one thousand, eighty-seven".