21003003121 has 8 divisors (see below), whose sum is σ = 21843701120. Its totient is φ = 20176676208.

The previous prime is 21003003103. The next prime is 21003003163. The reversal of 21003003121 is 12130030012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21003003121 - 2¹⁷ = 21002872049 is a prime.

It is a super-2 number, since 2×21003003121² (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 (21003003191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3589791 + ... + 3595636.

It is an arithmetic number, because the mean of its divisors is an integer number (2730462640).

Almost surely, 2^21003003121 is an apocalyptic number.

It is an amenable number.

21003003121 is a deficient number, since it is larger than the sum of its proper divisors (840697999).

21003003121 is an equidigital number, since it uses as much as digits as its factorization.

21003003121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7185543.

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

Adding to 21003003121 its reverse (12130030012), we get a palindrome (33133033133).

The spelling of 21003003121 in words is "twenty-one billion, three million, three thousand, one hundred twenty-one".