21163001321 has 16 divisors (see below), whose sum is σ = 26416947840. Its totient is φ = 16470708480.

The previous prime is 21163001317. The next prime is 21163001323. The reversal of 21163001321 is 12310036112.

It is a cyclic number.

It is not a de Polignac number, because 21163001321 - 2² = 21163001317 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21163001293 and 21163001302.

It is not an unprimeable number, because it can be changed into a prime (21163001323) 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, 101936 + ... + 229601.

It is an arithmetic number, because the mean of its divisors is an integer number (1651059240).

Almost surely, 2^21163001321 is an apocalyptic number.

It is an amenable number.

21163001321 is a deficient number, since it is larger than the sum of its proper divisors (5253946519).

21163001321 is a wasteful number, since it uses less digits than its factorization.

21163001321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332384.

The product of its (nonzero) digits is 216, while the sum is 20.

Adding to 21163001321 its reverse (12310036112), we get a palindrome (33473037433).

The spelling of 21163001321 in words is "twenty-one billion, one hundred sixty-three million, one thousand, three hundred twenty-one".