216787947 has 16 divisors (see below), whose sum is σ = 294602112. Its totient is φ = 141768000.

The previous prime is 216787943. The next prime is 216787957. The reversal of 216787947 is 749787612.

It is not a de Polignac number, because 216787947 - 2² = 216787943 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 216787947.

It is not an unprimeable number, because it can be changed into a prime (216787943) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 48303 + ... + 52599.

It is an arithmetic number, because the mean of its divisors is an integer number (18412632).

Almost surely, 2^216787947 is an apocalyptic number.

216787947 is a deficient number, since it is larger than the sum of its proper divisors (77814165).

216787947 is a wasteful number, since it uses less digits than its factorization.

216787947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4618.

The product of its digits is 1185408, while the sum is 51.

The square root of 216787947 is about 14723.7205556204. The cubic root of 216787947 is about 600.7286952028.

The spelling of 216787947 in words is "two hundred sixteen million, seven hundred eighty-seven thousand, nine hundred forty-seven".