216691241 has 4 divisors (see below), whose sum is σ = 233359812. Its totient is φ = 200022672.

The previous prime is 216691217. The next prime is 216691253. The reversal of 216691241 is 142196612.

216691241 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 62410000 + 154281241 = 7900^2 + 12421^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216691241 is a prime.

It is a super-2 number, since 2×216691241² = 93910187852240162, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 216691198 and 216691207.

It is not an unprimeable number, because it can be changed into a prime (216691261) 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, 8334266 + ... + 8334291.

It is an arithmetic number, because the mean of its divisors is an integer number (58339953).

Almost surely, 2^216691241 is an apocalyptic number.

It is an amenable number.

216691241 is a deficient number, since it is larger than the sum of its proper divisors (16668571).

216691241 is a wasteful number, since it uses less digits than its factorization.

216691241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16668570.

The product of its digits is 5184, while the sum is 32.

The square root of 216691241 is about 14720.4361688097. The cubic root of 216691241 is about 600.6393564266.

The spelling of 216691241 in words is "two hundred sixteen million, six hundred ninety-one thousand, two hundred forty-one".