135056821 has 2 divisors, whose sum is σ = 135056822. Its totient is φ = 135056820.

The previous prime is 135056813. The next prime is 135056843. The reversal of 135056821 is 128650531.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71216721 + 63840100 = 8439^2 + 7990^2 .

It is an emirp because it is prime and its reverse (128650531) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 135056821 - 2³ = 135056813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (135056861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67528410 + 67528411.

It is an arithmetic number, because the mean of its divisors is an integer number (67528411).

Almost surely, 2^135056821 is an apocalyptic number.

It is an amenable number.

135056821 is a deficient number, since it is larger than the sum of its proper divisors (1).

135056821 is an equidigital number, since it uses as much as digits as its factorization.

135056821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7200, while the sum is 31.

The square root of 135056821 is about 11621.3949679029. The cubic root of 135056821 is about 513.0647461620.

The spelling of 135056821 in words is "one hundred thirty-five million, fifty-six thousand, eight hundred twenty-one".