216644091 has 16 divisors (see below), whose sum is σ = 292615968. Its totient is φ = 142560000.

The previous prime is 216644083. The next prime is 216644117. The reversal of 216644091 is 190446612.

It is not a de Polignac number, because 216644091 - 2³ = 216644083 is a prime.

It is not an unprimeable number, because it can be changed into a prime (216644011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 119391 + ... + 121191.

It is an arithmetic number, because the mean of its divisors is an integer number (18288498).

Almost surely, 2^216644091 is an apocalyptic number.

216644091 is a deficient number, since it is larger than the sum of its proper divisors (75971877).

216644091 is a wasteful number, since it uses less digits than its factorization.

216644091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2302.

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 216644091 is about 14718.8345666360. The cubic root of 216644091 is about 600.5957887527.

The spelling of 216644091 in words is "two hundred sixteen million, six hundred forty-four thousand, ninety-one".