21002213321 has 8 divisors (see below), whose sum is σ = 22366182024. Its totient is φ = 19652527360.

The previous prime is 21002213251. The next prime is 21002213329. The reversal of 21002213321 is 12331220012.

It can be written as a sum of positive squares in 4 ways, for example, as 3156192400 + 17846020921 = 56180^2 + 133589^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21002213321 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

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 21002213321.

It is not an unprimeable number, because it can be changed into a prime (21002213329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3567650 + ... + 3573531.

It is an arithmetic number, because the mean of its divisors is an integer number (2795772753).

Almost surely, 2^21002213321 is an apocalyptic number.

It is an amenable number.

21002213321 is a deficient number, since it is larger than the sum of its proper divisors (1363968703).

21002213321 is a wasteful number, since it uses less digits than its factorization.

21002213321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7141371.

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 21002213321 its reverse (12331220012), we get a palindrome (33333433333).

The spelling of 21002213321 in words is "twenty-one billion, two million, two hundred thirteen thousand, three hundred twenty-one".