21201002321 has 4 divisors (see below), whose sum is σ = 21201881700. Its totient is φ = 21200122944.

The previous prime is 21201002293. The next prime is 21201002327. The reversal of 21201002321 is 12320010212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 12926553025 + 8274449296 = 113695^2 + 90964^2 .

It is a cyclic number.

It is not a de Polignac number, because 21201002321 - 2²⁶ = 21133893457 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21201002296 and 21201002305.

It is not an unprimeable number, because it can be changed into a prime (21201002327) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 402476 + ... + 452093.

It is an arithmetic number, because the mean of its divisors is an integer number (5300470425).

Almost surely, 2^21201002321 is an apocalyptic number.

It is an amenable number.

21201002321 is a deficient number, since it is larger than the sum of its proper divisors (879379).

21201002321 is an equidigital number, since it uses as much as digits as its factorization.

21201002321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 879378.

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 21201002321 its reverse (12320010212), we get a palindrome (33521012533).

The spelling of 21201002321 in words is "twenty-one billion, two hundred one million, two thousand, three hundred twenty-one".