135715021 has 4 divisors (see below), whose sum is σ = 146154652. Its totient is φ = 125275392.

The previous prime is 135715007. The next prime is 135715049. The reversal of 135715021 is 120517531.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 120517531 = 283 ⋅425857.

It can be written as a sum of positive squares in 2 ways, for example, as 93334921 + 42380100 = 9661^2 + 6510^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-135715021 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 (135715061) 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 in 3 ways as a sum of consecutive naturals, for example, 5219796 + ... + 5219821.

It is an arithmetic number, because the mean of its divisors is an integer number (36538663).

Almost surely, 2^135715021 is an apocalyptic number.

It is an amenable number.

135715021 is a deficient number, since it is larger than the sum of its proper divisors (10439631).

135715021 is a wasteful number, since it uses less digits than its factorization.

135715021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10439630.

The product of its (nonzero) digits is 1050, while the sum is 25.

The square root of 135715021 is about 11649.6790084534. The cubic root of 135715021 is about 513.8968702539.

The spelling of 135715021 in words is "one hundred thirty-five million, seven hundred fifteen thousand, twenty-one".