135405252221 has 2 divisors, whose sum is σ = 135405252222. Its totient is φ = 135405252220.

The previous prime is 135405252209. The next prime is 135405252239. The reversal of 135405252221 is 122252504531.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 135045960196 + 359292025 = 367486^2 + 18955^2 .

It is a cyclic number.

It is not a de Polignac number, because 135405252221 - 2³⁴ = 118225383037 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (135405252251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67702626110 + 67702626111.

It is an arithmetic number, because the mean of its divisors is an integer number (67702626111).

Almost surely, 2^135405252221 is an apocalyptic number.

It is an amenable number.

135405252221 is a deficient number, since it is larger than the sum of its proper divisors (1).

135405252221 is an equidigital number, since it uses as much as digits as its factorization.

135405252221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24000, while the sum is 32.

Adding to 135405252221 its reverse (122252504531), we get a palindrome (257657756752).

The spelling of 135405252221 in words is "one hundred thirty-five billion, four hundred five million, two hundred fifty-two thousand, two hundred twenty-one".