216393937 has 2 divisors, whose sum is σ = 216393938. Its totient is φ = 216393936.

The previous prime is 216393929. The next prime is 216393953. The reversal of 216393937 is 739393612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 133656721 + 82737216 = 11561^2 + 9096^2 .

It is a cyclic number.

It is not a de Polignac number, because 216393937 - 2³ = 216393929 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 216393893 and 216393902.

It is not a weakly prime, because it can be changed into another prime (216393917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108196968 + 108196969.

It is an arithmetic number, because the mean of its divisors is an integer number (108196969).

Almost surely, 2^216393937 is an apocalyptic number.

It is an amenable number.

216393937 is a deficient number, since it is larger than the sum of its proper divisors (1).

216393937 is an equidigital number, since it uses as much as digits as its factorization.

216393937 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 183708, while the sum is 43.

The square root of 216393937 is about 14710.3343605779. The cubic root of 216393937 is about 600.3645349604.

It can be divided in two parts, 2163 and 93937, that added together give a square (96100 = 310²).

The spelling of 216393937 in words is "two hundred sixteen million, three hundred ninety-three thousand, nine hundred thirty-seven".