21051335 has 32 divisors (see below), whose sum is σ = 28071360. Its totient is φ = 15095808.

The previous prime is 21051323. The next prime is 21051337. The reversal of 21051335 is 53315012.

It is a cyclic number.

It is not a de Polignac number, because 21051335 - 2⁶ = 21051271 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21051337) 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 31 ways as a sum of consecutive naturals, for example, 186239 + ... + 186351.

It is an arithmetic number, because the mean of its divisors is an integer number (877230).

Almost surely, 2^21051335 is an apocalyptic number.

21051335 is a deficient number, since it is larger than the sum of its proper divisors (7020025).

21051335 is a wasteful number, since it uses less digits than its factorization.

21051335 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 227.

The product of its (nonzero) digits is 450, while the sum is 20.

The square root of 21051335 is about 4588.1733838206. The cubic root of 21051335 is about 276.1170432311.

Adding to 21051335 its reverse (53315012), we get a palindrome (74366347).

The spelling of 21051335 in words is "twenty-one million, fifty-one thousand, three hundred thirty-five".