21002031321 has 8 divisors (see below), whose sum is σ = 28006190784. Its totient is φ = 13999613040.

The previous prime is 21002031317. The next prime is 21002031359. The reversal of 21002031321 is 12313020012.

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

It is not a de Polignac number, because 21002031321 - 2² = 21002031317 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21002031321.

It is not an unprimeable number, because it can be changed into a prime (21002031301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 406885 + ... + 455586.

It is an arithmetic number, because the mean of its divisors is an integer number (3500773848).

Almost surely, 2^21002031321 is an apocalyptic number.

It is an amenable number.

21002031321 is a deficient number, since it is larger than the sum of its proper divisors (7004159463).

21002031321 is an equidigital number, since it uses as much as digits as its factorization.

21002031321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 870591.

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21002031321 its reverse (12313020012), we get a palindrome (33315051333).

The spelling of 21002031321 in words is "twenty-one billion, two million, thirty-one thousand, three hundred twenty-one".