216506501 has 6 divisors (see below), whose sum is σ = 228501702. Its totient is φ = 205111080.

The previous prime is 216506483. The next prime is 216506513. The reversal of 216506501 is 105605612.

It can be written as a sum of positive squares in only one way, i.e., 152522500 + 63984001 = 12350^2 + 7999^2 .

It is not a de Polignac number, because 216506501 - 2²⁶ = 149397637 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216506561) 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 5 ways as a sum of consecutive naturals, for example, 299510 + ... + 300231.

It is an arithmetic number, because the mean of its divisors is an integer number (38083617).

Almost surely, 2^216506501 is an apocalyptic number.

It is an amenable number.

216506501 is a deficient number, since it is larger than the sum of its proper divisors (11995201).

216506501 is an equidigital number, since it uses as much as digits as its factorization.

216506501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 599779 (or 599760 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 216506501 is about 14714.1598808767. The cubic root of 216506501 is about 600.4686163100.

The spelling of 216506501 in words is "two hundred sixteen million, five hundred six thousand, five hundred one".