21003631321 has 16 divisors (see below), whose sum is σ = 22039804800. Its totient is φ = 19988615808.

The previous prime is 21003631289. The next prime is 21003631357. The reversal of 21003631321 is 12313630012.

It is a cyclic number.

It is not a de Polignac number, because 21003631321 - 2⁵ = 21003631289 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21003631292 and 21003631301.

It is not an unprimeable number, because it can be changed into a prime (21003631421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5457820 + ... + 5461666.

It is an arithmetic number, because the mean of its divisors is an integer number (1377487800).

Almost surely, 2^21003631321 is an apocalyptic number.

It is an amenable number.

21003631321 is a deficient number, since it is larger than the sum of its proper divisors (1036173479).

21003631321 is a wasteful number, since it uses less digits than its factorization.

21003631321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6528.

The product of its (nonzero) digits is 648, while the sum is 22.

The spelling of 21003631321 in words is "twenty-one billion, three million, six hundred thirty-one thousand, three hundred twenty-one".