216005806 has 8 divisors (see below), whose sum is σ = 324544320. Its totient is φ = 107824368.

The previous prime is 216005767. The next prime is 216005809. The reversal of 216005806 is 608500612.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216005809) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 87751 + ... + 90178.

It is an arithmetic number, because the mean of its divisors is an integer number (40568040).

Almost surely, 2^216005806 is an apocalyptic number.

216005806 is a deficient number, since it is larger than the sum of its proper divisors (108538514).

216005806 is a wasteful number, since it uses less digits than its factorization.

216005806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178538.

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 216005806 is about 14697.1359795029. The cubic root of 216005806 is about 600.0053758778.

It can be divided in two parts, 216005 and 806, that added together give a triangular number (216811 = T₆₅₈).

The spelling of 216005806 in words is "two hundred sixteen million, five thousand, eight hundred six".