216531655 has 8 divisors (see below), whose sum is σ = 259935984. Its totient is φ = 173160000.

The previous prime is 216531643. The next prime is 216531677. The reversal of 216531655 is 556135612.

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

It is not a de Polignac number, because 216531655 - 2⁹ = 216531143 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 216531655.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10155 + ... + 23155.

It is an arithmetic number, because the mean of its divisors is an integer number (32491998).

Almost surely, 2^216531655 is an apocalyptic number.

216531655 is a deficient number, since it is larger than the sum of its proper divisors (43404329).

216531655 is a wasteful number, since it uses less digits than its factorization.

216531655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16337.

The product of its digits is 27000, while the sum is 34.

The square root of 216531655 is about 14715.0146109340. The cubic root of 216531655 is about 600.4918698114.

The spelling of 216531655 in words is "two hundred sixteen million, five hundred thirty-one thousand, six hundred fifty-five".