135547021 has 4 divisors (see below), whose sum is σ = 139210492. Its totient is φ = 131883552.

The previous prime is 135546991. The next prime is 135547039. The reversal of 135547021 is 120745531.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 100902025 + 34644996 = 10045^2 + 5886^2 .

It is a cyclic number.

It is not a de Polignac number, because 135547021 - 2⁵ = 135546989 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 (135542021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1831680 + ... + 1831753.

It is an arithmetic number, because the mean of its divisors is an integer number (34802623).

Almost surely, 2^135547021 is an apocalyptic number.

It is an amenable number.

135547021 is a deficient number, since it is larger than the sum of its proper divisors (3663471).

135547021 is an equidigital number, since it uses as much as digits as its factorization.

135547021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3663470.

The product of its (nonzero) digits is 4200, while the sum is 28.

The square root of 135547021 is about 11642.4662765241. The cubic root of 135547021 is about 513.6847337679.

The spelling of 135547021 in words is "one hundred thirty-five million, five hundred forty-seven thousand, twenty-one".