21058135 has 16 divisors (see below), whose sum is σ = 29154816. Its totient is φ = 14302368.

The previous prime is 21058129. The next prime is 21058151. The reversal of 21058135 is 53185012.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21058135 - 2⁹ = 21057623 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 934 + ... + 6556.

It is an arithmetic number, because the mean of its divisors is an integer number (1822176).

Almost surely, 2^21058135 is an apocalyptic number.

21058135 is a deficient number, since it is larger than the sum of its proper divisors (8096681).

21058135 is a wasteful number, since it uses less digits than its factorization.

21058135 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5742.

The product of its (nonzero) digits is 1200, while the sum is 25.

The square root of 21058135 is about 4588.9143596280. The cubic root of 21058135 is about 276.1467704632.

The spelling of 21058135 in words is "twenty-one million, fifty-eight thousand, one hundred thirty-five".