216538237 has 2 divisors, whose sum is σ = 216538238. Its totient is φ = 216538236.

The previous prime is 216538229. The next prime is 216538247. The reversal of 216538237 is 732835612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 184660921 + 31877316 = 13589^2 + 5646^2 .

It is a cyclic number.

It is not a de Polignac number, because 216538237 - 2³ = 216538229 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 216538196 and 216538205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216538207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108269118 + 108269119.

It is an arithmetic number, because the mean of its divisors is an integer number (108269119).

Almost surely, 2^216538237 is an apocalyptic number.

It is an amenable number.

216538237 is a deficient number, since it is larger than the sum of its proper divisors (1).

216538237 is an equidigital number, since it uses as much as digits as its factorization.

216538237 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 60480, while the sum is 37.

The square root of 216538237 is about 14715.2382583497. The cubic root of 216538237 is about 600.4979542143.

It can be divided in two parts, 21653 and 8237, that added together give a triangular number (29890 = T₂₄₄).

The spelling of 216538237 in words is "two hundred sixteen million, five hundred thirty-eight thousand, two hundred thirty-seven".