135123217 has 2 divisors, whose sum is σ = 135123218. Its totient is φ = 135123216.

The previous prime is 135123173. The next prime is 135123221. The reversal of 135123217 is 712321531.

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., 125238481 + 9884736 = 11191^2 + 3144^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-135123217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 135123191 and 135123200.

It is not a weakly prime, because it can be changed into another prime (135123227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67561608 + 67561609.

It is an arithmetic number, because the mean of its divisors is an integer number (67561609).

Almost surely, 2^135123217 is an apocalyptic number.

It is an amenable number.

135123217 is a deficient number, since it is larger than the sum of its proper divisors (1).

135123217 is an equidigital number, since it uses as much as digits as its factorization.

135123217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1260, while the sum is 25.

The square root of 135123217 is about 11624.2512447039. The cubic root of 135123217 is about 513.1488092149.

Adding to 135123217 its reverse (712321531), we get a palindrome (847444748).

The spelling of 135123217 in words is "one hundred thirty-five million, one hundred twenty-three thousand, two hundred seventeen".