216615671 has 4 divisors (see below), whose sum is σ = 216647592. Its totient is φ = 216583752.

The previous prime is 216615661. The next prime is 216615677. The reversal of 216615671 is 176516612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 216615671 - 2¹⁰ = 216614647 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216615677) 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 in 3 ways as a sum of consecutive naturals, for example, 1280 + ... + 20853.

It is an arithmetic number, because the mean of its divisors is an integer number (54161898).

Almost surely, 2^216615671 is an apocalyptic number.

216615671 is a deficient number, since it is larger than the sum of its proper divisors (31921).

216615671 is an equidigital number, since it uses as much as digits as its factorization.

216615671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31920.

The product of its digits is 15120, while the sum is 35.

The square root of 216615671 is about 14717.8691052747. The cubic root of 216615671 is about 600.5695249719.

The spelling of 216615671 in words is "two hundred sixteen million, six hundred fifteen thousand, six hundred seventy-one".