21310021003 has 4 divisors (see below), whose sum is σ = 21566768328. Its totient is φ = 21053273680.

The previous prime is 21310021001. The next prime is 21310021009. The reversal of 21310021003 is 30012001312.

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 21310021003 - 2¹ = 21310021001 is a prime.

It is a super-2 number, since 2×21310021003² (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 (21310021001) 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, 128373538 + ... + 128373703.

It is an arithmetic number, because the mean of its divisors is an integer number (5391692082).

Almost surely, 2^21310021003 is an apocalyptic number.

21310021003 is a deficient number, since it is larger than the sum of its proper divisors (256747325).

21310021003 is an equidigital number, since it uses as much as digits as its factorization.

21310021003 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 256747324.

The product of its (nonzero) digits is 36, while the sum is 13.

Adding to 21310021003 its reverse (30012001312), we get a palindrome (51322022315).

The spelling of 21310021003 in words is "twenty-one billion, three hundred ten million, twenty-one thousand, three".