215697871 has 2 divisors, whose sum is σ = 215697872. Its totient is φ = 215697870.

The previous prime is 215697851. The next prime is 215697877. The reversal of 215697871 is 178796512.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 215697871 - 2¹³ = 215689679 is a prime.

It is equal to p_11898667 and since 215697871 and 11898667 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (215697877) 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, 107848935 + 107848936.

It is an arithmetic number, because the mean of its divisors is an integer number (107848936).

Almost surely, 2^215697871 is an apocalyptic number.

215697871 is a deficient number, since it is larger than the sum of its proper divisors (1).

215697871 is an equidigital number, since it uses as much as digits as its factorization.

215697871 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 211680, while the sum is 46.

The square root of 215697871 is about 14686.6562225716. The cubic root of 215697871 is about 599.7201203919.

The spelling of 215697871 in words is "two hundred fifteen million, six hundred ninety-seven thousand, eight hundred seventy-one".