135840121357 has 2 divisors, whose sum is σ = 135840121358. Its totient is φ = 135840121356.

The previous prime is 135840121343. The next prime is 135840121399. The reversal of 135840121357 is 753121048531.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 116426993796 + 19413127561 = 341214^2 + 139331^2 .

It is a cyclic number.

It is not a de Polignac number, because 135840121357 - 2¹¹ = 135840119309 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (135840125357) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67920060678 + 67920060679.

It is an arithmetic number, because the mean of its divisors is an integer number (67920060679).

Almost surely, 2^135840121357 is an apocalyptic number.

It is an amenable number.

135840121357 is a deficient number, since it is larger than the sum of its proper divisors (1).

135840121357 is an equidigital number, since it uses as much as digits as its factorization.

135840121357 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 100800, while the sum is 40.

Adding to 135840121357 its reverse (753121048531), we get a palindrome (888961169888).

The spelling of 135840121357 in words is "one hundred thirty-five billion, eight hundred forty million, one hundred twenty-one thousand, three hundred fifty-seven".