216257947 has 2 divisors, whose sum is σ = 216257948. Its totient is φ = 216257946.

The previous prime is 216257929. The next prime is 216257957. The reversal of 216257947 is 749752612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 216257947 - 2¹¹ = 216255899 is a prime.

It is not a weakly prime, because it can be changed into another prime (216257917) 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, 108128973 + 108128974.

It is an arithmetic number, because the mean of its divisors is an integer number (108128974).

Almost surely, 2^216257947 is an apocalyptic number.

216257947 is a deficient number, since it is larger than the sum of its proper divisors (1).

216257947 is an equidigital number, since it uses as much as digits as its factorization.

216257947 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 211680, while the sum is 43.

The square root of 216257947 is about 14705.7113734766. The cubic root of 216257947 is about 600.2387448037.

The spelling of 216257947 in words is "two hundred sixteen million, two hundred fifty-seven thousand, nine hundred forty-seven".