135558821 has 8 divisors (see below), whose sum is σ = 136656120. Its totient is φ = 134465472.

The previous prime is 135558791. The next prime is 135558823. The reversal of 135558821 is 128855531.

It can be written as a sum of positive squares in 4 ways, for example, as 87796900 + 47761921 = 9370^2 + 6911^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 135558821 - 2¹⁰ = 135557797 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (135558823) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 126275 + ... + 127343.

It is an arithmetic number, because the mean of its divisors is an integer number (17082015).

Almost surely, 2^135558821 is an apocalyptic number.

It is an amenable number.

135558821 is a deficient number, since it is larger than the sum of its proper divisors (1097299).

135558821 is a wasteful number, since it uses less digits than its factorization.

135558821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1975.

The product of its digits is 48000, while the sum is 38.

The square root of 135558821 is about 11642.9730309745. The cubic root of 135558821 is about 513.6996395522.

The spelling of 135558821 in words is "one hundred thirty-five million, five hundred fifty-eight thousand, eight hundred twenty-one".