216207389 has 2 divisors, whose sum is σ = 216207390. Its totient is φ = 216207388.

The previous prime is 216207371. The next prime is 216207427. The reversal of 216207389 is 983702612.

It is an a-pointer prime, because the next prime (216207427) can be obtained adding 216207389 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 157301764 + 58905625 = 12542^2 + 7675^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216207389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216207319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108103694 + 108103695.

It is an arithmetic number, because the mean of its divisors is an integer number (108103695).

Almost surely, 2^216207389 is an apocalyptic number.

It is an amenable number.

216207389 is a deficient number, since it is larger than the sum of its proper divisors (1).

216207389 is an equidigital number, since it uses as much as digits as its factorization.

216207389 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36288, while the sum is 38.

The square root of 216207389 is about 14703.9922810099. The cubic root of 216207389 is about 600.1919654274.

The spelling of 216207389 in words is "two hundred sixteen million, two hundred seven thousand, three hundred eighty-nine".