217470989 has 2 divisors, whose sum is σ = 217470990. Its totient is φ = 217470988.

The previous prime is 217470961. The next prime is 217471019. The reversal of 217470989 is 989074712.

217470989 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., 114854089 + 102616900 = 10717^2 + 10130^2 .

It is a cyclic number.

It is not a de Polignac number, because 217470989 - 2⁸ = 217470733 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (217470689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108735494 + 108735495.

It is an arithmetic number, because the mean of its divisors is an integer number (108735495).

Almost surely, 2^217470989 is an apocalyptic number.

It is an amenable number.

217470989 is a deficient number, since it is larger than the sum of its proper divisors (1).

217470989 is an equidigital number, since it uses as much as digits as its factorization.

217470989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 254016, while the sum is 47.

The square root of 217470989 is about 14746.8976059373. The cubic root of 217470989 is about 601.3589466349.

The spelling of 217470989 in words is "two hundred seventeen million, four hundred seventy thousand, nine hundred eighty-nine".