216638841 has 8 divisors (see below), whose sum is σ = 289044000. Its totient is φ = 144329792.

The previous prime is 216638831. The next prime is 216638861. The reversal of 216638841 is 148836612.

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

It is a cyclic number.

It is not a de Polignac number, because 216638841 - 2⁷ = 216638713 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 216638841.

It is not an unprimeable number, because it can be changed into a prime (216638831) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18591 + ... + 27908.

It is an arithmetic number, because the mean of its divisors is an integer number (36130500).

Almost surely, 2^216638841 is an apocalyptic number.

It is an amenable number.

216638841 is a deficient number, since it is larger than the sum of its proper divisors (72405159).

216638841 is a wasteful number, since it uses less digits than its factorization.

216638841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48055.

The product of its digits is 55296, while the sum is 39.

The square root of 216638841 is about 14718.6562226312. The cubic root of 216638841 is about 600.5909372420.

The spelling of 216638841 in words is "two hundred sixteen million, six hundred thirty-eight thousand, eight hundred forty-one".