216207681 has 8 divisors (see below), whose sum is σ = 288696864. Its totient is φ = 143928480.

The previous prime is 216207679. The next prime is 216207701. The reversal of 216207681 is 186702612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 216207681 - 2¹ = 216207679 is a prime.

It is a super-2 number, since 2×216207681² = 93491522646795522, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (216207181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50076 + ... + 54221.

It is an arithmetic number, because the mean of its divisors is an integer number (36087108).

Almost surely, 2^216207681 is an apocalyptic number.

It is an amenable number.

216207681 is a deficient number, since it is larger than the sum of its proper divisors (72489183).

216207681 is a wasteful number, since it uses less digits than its factorization.

216207681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104991.

The product of its (nonzero) digits is 8064, while the sum is 33.

The square root of 216207681 is about 14704.0022102828. The cubic root of 216207681 is about 600.1922356248.

The spelling of 216207681 in words is "two hundred sixteen million, two hundred seven thousand, six hundred eighty-one".