21002320033 has 4 divisors (see below), whose sum is σ = 21003418260. Its totient is φ = 21001221808.

The previous prime is 21002319971. The next prime is 21002320037. The reversal of 21002320033 is 33002320012.

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 9157915809 + 11844404224 = 95697^2 + 108832^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21002320033 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21002319989 and 21002320016.

It is not an unprimeable number, because it can be changed into a prime (21002320037) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 519910 + ... + 558847.

It is an arithmetic number, because the mean of its divisors is an integer number (5250854565).

Almost surely, 2^21002320033 is an apocalyptic number.

It is an amenable number.

21002320033 is a deficient number, since it is larger than the sum of its proper divisors (1098227).

21002320033 is a wasteful number, since it uses less digits than its factorization.

21002320033 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1098226.

The product of its (nonzero) digits is 216, while the sum is 16.

Adding to 21002320033 its reverse (33002320012), we get a palindrome (54004640045).

The spelling of 21002320033 in words is "twenty-one billion, two million, three hundred twenty thousand, thirty-three".