20505135 has 32 divisors (see below), whose sum is σ = 37665792. Its totient is φ = 9331200.

The previous prime is 20505127. The next prime is 20505151. The reversal of 20505135 is 53150502.

It is not a de Polignac number, because 20505135 - 2³ = 20505127 is a prime.

It is a super-2 number, since 2×20505135² = 840921122736450, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 41862 + ... + 42348.

It is an arithmetic number, because the mean of its divisors is an integer number (1177056).

Almost surely, 2^20505135 is an apocalyptic number.

20505135 is a deficient number, since it is larger than the sum of its proper divisors (17160657).

20505135 is a wasteful number, since it uses less digits than its factorization.

20505135 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 903.

The product of its (nonzero) digits is 750, while the sum is 21.

The square root of 20505135 is about 4528.2595994488. The cubic root of 20505135 is about 273.7080334325.

Adding to 20505135 its reverse (53150502), we get a palindrome (73655637).

The spelling of 20505135 in words is "twenty million, five hundred five thousand, one hundred thirty-five".