216601001 has 8 divisors (see below), whose sum is σ = 219978024. Its totient is φ = 213235200.

The previous prime is 216600947. The next prime is 216601031. The reversal of 216601001 is 100106612.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 65286400 + 151314601 = 8080^2 + 12301^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216601001 is a prime.

It is a super-3 number, since 3×216601001³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216601031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41405 + ... + 46341.

It is an arithmetic number, because the mean of its divisors is an integer number (27497253).

Almost surely, 2^216601001 is an apocalyptic number.

It is an amenable number.

216601001 is a deficient number, since it is larger than the sum of its proper divisors (3377023).

216601001 is an equidigital number, since it uses as much as digits as its factorization.

216601001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5611.

The product of its (nonzero) digits is 72, while the sum is 17.

The square root of 216601001 is about 14717.3707230606. The cubic root of 216601001 is about 600.5559670826. Note that the first 3 decimals are identical.

Adding to 216601001 its reverse (100106612), we get a palindrome (316707613).

The spelling of 216601001 in words is "two hundred sixteen million, six hundred one thousand, one".