21320002331 has 4 divisors (see below), whose sum is σ = 21508675032. Its totient is φ = 21131329632.

The previous prime is 21320002321. The next prime is 21320002343. The reversal of 21320002331 is 13320002312.

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

It is a cyclic number.

It is not a de Polignac number, because 21320002331 - 2⁶ = 21320002267 is a prime.

It is a super-2 number, since 2×21320002331² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21320002321) 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, 94336181 + ... + 94336406.

It is an arithmetic number, because the mean of its divisors is an integer number (5377168758).

Almost surely, 2^21320002331 is an apocalyptic number.

21320002331 is a deficient number, since it is larger than the sum of its proper divisors (188672701).

21320002331 is a wasteful number, since it uses less digits than its factorization.

21320002331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188672700.

The product of its (nonzero) digits is 216, while the sum is 17.

Adding to 21320002331 its reverse (13320002312), we get a palindrome (34640004643).

The spelling of 21320002331 in words is "twenty-one billion, three hundred twenty million, two thousand, three hundred thirty-one".