217323157 has 2 divisors, whose sum is σ = 217323158. Its totient is φ = 217323156.

The previous prime is 217323131. The next prime is 217323181. The reversal of 217323157 is 751323712.

217323157 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 132848676 + 84474481 = 11526^2 + 9191^2 .

It is a cyclic number.

It is not a de Polignac number, because 217323157 - 2¹¹ = 217321109 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (217623157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108661578 + 108661579.

It is an arithmetic number, because the mean of its divisors is an integer number (108661579).

Almost surely, 2^217323157 is an apocalyptic number.

It is an amenable number.

217323157 is a deficient number, since it is larger than the sum of its proper divisors (1).

217323157 is an equidigital number, since it uses as much as digits as its factorization.

217323157 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8820, while the sum is 31.

The square root of 217323157 is about 14741.8844453482. The cubic root of 217323157 is about 601.2226522140. Note that the first 3 decimals are identical.

Adding to 217323157 its reverse (751323712), we get a palindrome (968646869).

The spelling of 217323157 in words is "two hundred seventeen million, three hundred twenty-three thousand, one hundred fifty-seven".