135079821 has 6 divisors (see below), whose sum is σ = 195115310. Its totient is φ = 90053208.

The previous prime is 135079751. The next prime is 135079823. The reversal of 135079821 is 128970531.

It can be written as a sum of positive squares in only one way, i.e., 73770921 + 61308900 = 8589^2 + 7830^2 .

It is not a de Polignac number, because 135079821 - 2⁹ = 135079309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (135079823) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7504426 + ... + 7504443.

Almost surely, 2^135079821 is an apocalyptic number.

It is an amenable number.

135079821 is a deficient number, since it is larger than the sum of its proper divisors (60035489).

135079821 is a wasteful number, since it uses less digits than its factorization.

135079821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15008875 (or 15008872 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 36.

The square root of 135079821 is about 11622.3844799594. The cubic root of 135079821 is about 513.0938692607.

The spelling of 135079821 in words is "one hundred thirty-five million, seventy-nine thousand, eight hundred twenty-one".