21000313033 has 18 divisors (see below), whose sum is σ = 24773802954. Its totient is φ = 17746362144.

The previous prime is 21000312947. The next prime is 21000313057. The reversal of 21000313033 is 33031300012.

It can be written as a sum of positive squares in only one way, i.e., 18411233344 + 2589079689 = 135688^2 + 50883^2 .

It is not a de Polignac number, because 21000313033 - 2²¹ = 20998215881 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21000312998 and 21000313016.

It is not an unprimeable number, because it can be changed into a prime (21000313933) 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 17 ways as a sum of consecutive naturals, for example, 8665860 + ... + 8668282.

Almost surely, 2^21000313033 is an apocalyptic number.

It is an amenable number.

21000313033 is a deficient number, since it is larger than the sum of its proper divisors (3773489921).

21000313033 is an frugal number, since it uses more digits than its factorization.

21000313033 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4933 (or 2503 counting only the distinct ones).

The product of its (nonzero) digits is 162, while the sum is 16.

Adding to 21000313033 its reverse (33031300012), we get a palindrome (54031613045).

The spelling of 21000313033 in words is "twenty-one billion, three hundred thirteen thousand, thirty-three".