210240257 has 2 divisors, whose sum is σ = 210240258. Its totient is φ = 210240256.

The previous prime is 210240223. The next prime is 210240271. The reversal of 210240257 is 752042012.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 209931121 + 309136 = 14489^2 + 556^2 .

It is a cyclic number.

It is not a de Polignac number, because 210240257 - 2⁶ = 210240193 is a prime.

It is not a weakly prime, because it can be changed into another prime (210240157) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105120128 + 105120129.

It is an arithmetic number, because the mean of its divisors is an integer number (105120129).

Almost surely, 2^210240257 is an apocalyptic number.

It is an amenable number.

210240257 is a deficient number, since it is larger than the sum of its proper divisors (1).

210240257 is an equidigital number, since it uses as much as digits as its factorization.

210240257 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1120, while the sum is 23.

The square root of 210240257 is about 14499.6640305905. The cubic root of 210240257 is about 594.6187864817.

Adding to 210240257 its reverse (752042012), we get a palindrome (962282269).

The spelling of 210240257 in words is "two hundred ten million, two hundred forty thousand, two hundred fifty-seven".