21035321 has 4 divisors (see below), whose sum is σ = 21065700. Its totient is φ = 21004944.

The previous prime is 21035303. The next prime is 21035327. The reversal of 21035321 is 12353012.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1357225 + 19678096 = 1165^2 + 4436^2 .

It is a cyclic number.

It is not a de Polignac number, because 21035321 - 2¹⁰ = 21034297 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21035321.

It is not an unprimeable number, because it can be changed into a prime (21035327) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14126 + ... + 15543.

It is an arithmetic number, because the mean of its divisors is an integer number (5266425).

Almost surely, 2^21035321 is an apocalyptic number.

It is an amenable number.

21035321 is a deficient number, since it is larger than the sum of its proper divisors (30379).

21035321 is an equidigital number, since it uses as much as digits as its factorization.

21035321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30378.

The product of its (nonzero) digits is 180, while the sum is 17.

The square root of 21035321 is about 4586.4279128751. The cubic root of 21035321 is about 276.0470103009.

Adding to 21035321 its reverse (12353012), we get a palindrome (33388333).

The spelling of 21035321 in words is "twenty-one million, thirty-five thousand, three hundred twenty-one".