216955601 has 4 divisors (see below), whose sum is σ = 217005492. Its totient is φ = 216905712.

The previous prime is 216955579. The next prime is 216955621. The reversal of 216955601 is 106559612.

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 144024001 + 72931600 = 12001^2 + 8540^2 .

It is a cyclic number.

It is not a de Polignac number, because 216955601 - 2⁶ = 216955537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216955621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17726 + ... + 27351.

It is an arithmetic number, because the mean of its divisors is an integer number (54251373).

Almost surely, 2^216955601 is an apocalyptic number.

It is an amenable number.

216955601 is a deficient number, since it is larger than the sum of its proper divisors (49891).

216955601 is an equidigital number, since it uses as much as digits as its factorization.

216955601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49890.

The product of its (nonzero) digits is 16200, while the sum is 35.

The square root of 216955601 is about 14729.4127853082. The cubic root of 216955601 is about 600.8835141069.

The spelling of 216955601 in words is "two hundred sixteen million, nine hundred fifty-five thousand, six hundred one".