216722805 has 16 divisors (see below), whose sum is σ = 373430400. Its totient is φ = 106694208.

The previous prime is 216722789. The next prime is 216722827. The reversal of 216722805 is 508227612.

It is not a de Polignac number, because 216722805 - 2⁴ = 216722789 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 555505 + ... + 555894.

It is an arithmetic number, because the mean of its divisors is an integer number (23339400).

Almost surely, 2^216722805 is an apocalyptic number.

It is an amenable number.

216722805 is a deficient number, since it is larger than the sum of its proper divisors (156707595).

216722805 is a wasteful number, since it uses less digits than its factorization.

216722805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1111420.

The product of its (nonzero) digits is 13440, while the sum is 33.

The square root of 216722805 is about 14721.5082447418. The cubic root of 216722805 is about 600.6685187500.

The spelling of 216722805 in words is "two hundred sixteen million, seven hundred twenty-two thousand, eight hundred five".