21031135 has 4 divisors (see below), whose sum is σ = 25237368. Its totient is φ = 16824904.

The previous prime is 21031111. The next prime is 21031151. The reversal of 21031135 is 53113012.

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

It is a cyclic number.

It is not a de Polignac number, because 21031135 - 2⁵ = 21031103 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 (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2103109 + ... + 2103118.

It is an arithmetic number, because the mean of its divisors is an integer number (6309342).

Almost surely, 2^21031135 is an apocalyptic number.

21031135 is a deficient number, since it is larger than the sum of its proper divisors (4206233).

21031135 is an equidigital number, since it uses as much as digits as its factorization.

21031135 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4206232.

The product of its (nonzero) digits is 90, while the sum is 16.

The square root of 21031135 is about 4585.9715437408. The cubic root of 21031135 is about 276.0286980941.

Adding to 21031135 its reverse (53113012), we get a palindrome (74144147).

The spelling of 21031135 in words is "twenty-one million, thirty-one thousand, one hundred thirty-five".