21013321 has 8 divisors (see below), whose sum is σ = 24177600. Its totient is φ = 17889648.

The previous prime is 21013303. The next prime is 21013357. The reversal of 21013321 is 12331012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21013321 - 2¹³ = 21005129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21013301) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9031 + ... + 11116.

It is an arithmetic number, because the mean of its divisors is an integer number (3022200).

Almost surely, 2^21013321 is an apocalyptic number.

It is an amenable number.

21013321 is a deficient number, since it is larger than the sum of its proper divisors (3164279).

21013321 is a wasteful number, since it uses less digits than its factorization.

21013321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20303.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 21013321 is about 4584.0289047954. The cubic root of 21013321 is about 275.9507412266.

Adding to 21013321 its reverse (12331012), we get a palindrome (33344333).

It can be divided in two parts, 210 and 13321, that added together give a palindrome (13531).

The spelling of 21013321 in words is "twenty-one million, thirteen thousand, three hundred twenty-one".