216723237 has 4 divisors (see below), whose sum is σ = 288964320. Its totient is φ = 144482156.

The previous prime is 216723233. The next prime is 216723281. The reversal of 216723237 is 732327612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 216723237 - 2² = 216723233 is a prime.

It is a super-2 number, since 2×216723237² = 93937922911516338, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 216723198 and 216723207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216723233) 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, 36120537 + ... + 36120542.

It is an arithmetic number, because the mean of its divisors is an integer number (72241080).

Almost surely, 2^216723237 is an apocalyptic number.

It is an amenable number.

216723237 is a deficient number, since it is larger than the sum of its proper divisors (72241083).

216723237 is an equidigital number, since it uses as much as digits as its factorization.

216723237 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72241082.

The product of its digits is 21168, while the sum is 33.

The square root of 216723237 is about 14721.5229171441. The cubic root of 216723237 is about 600.6689178599.

The spelling of 216723237 in words is "two hundred sixteen million, seven hundred twenty-three thousand, two hundred thirty-seven".