216538901 has 2 divisors, whose sum is σ = 216538902. Its totient is φ = 216538900.

The previous prime is 216538891. The next prime is 216538919. The reversal of 216538901 is 109835612.

216538901 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 124858276 + 91680625 = 11174^2 + 9575^2 .

It is a cyclic number.

It is not a de Polignac number, because 216538901 - 2¹⁰ = 216537877 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216538981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108269450 + 108269451.

It is an arithmetic number, because the mean of its divisors is an integer number (108269451).

Almost surely, 2^216538901 is an apocalyptic number.

It is an amenable number.

216538901 is a deficient number, since it is larger than the sum of its proper divisors (1).

216538901 is an equidigital number, since it uses as much as digits as its factorization.

216538901 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12960, while the sum is 35.

The square root of 216538901 is about 14715.2608199787. The cubic root of 216538901 is about 600.4985680092.

The spelling of 216538901 in words is "two hundred sixteen million, five hundred thirty-eight thousand, nine hundred one".