21335828 has 12 divisors (see below), whose sum is σ = 38347092. Its totient is φ = 10379520.

The previous prime is 21335827. The next prime is 21335849. The reversal of 21335828 is 82853312.

It can be written as a sum of positive squares in 2 ways, for example, as 14002564 + 7333264 = 3742^2 + 2708^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21335794 and 21335803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21335827) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 71933 + ... + 72228.

It is an arithmetic number, because the mean of its divisors is an integer number (3195591).

Almost surely, 2^21335828 is an apocalyptic number.

It is an amenable number.

21335828 is a deficient number, since it is larger than the sum of its proper divisors (17011264).

21335828 is a wasteful number, since it uses less digits than its factorization.

21335828 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144202 (or 144200 counting only the distinct ones).

The product of its digits is 11520, while the sum is 32.

The square root of 21335828 is about 4619.0722012110. The cubic root of 21335828 is about 277.3553199768.

The spelling of 21335828 in words is "twenty-one million, three hundred thirty-five thousand, eight hundred twenty-eight".