21003003031 has 4 divisors (see below), whose sum is σ = 21003301792. Its totient is φ = 21002704272.

The previous prime is 21003003029. The next prime is 21003003059. The reversal of 21003003031 is 13030030012.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21003003031 - 2¹ = 21003003029 is a prime.

It is a super-2 number, since 2×21003003031² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21003003331) 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 3 ways as a sum of consecutive naturals, for example, 20371 + ... + 205963.

It is an arithmetic number, because the mean of its divisors is an integer number (5250825448).

Almost surely, 2^21003003031 is an apocalyptic number.

21003003031 is a deficient number, since it is larger than the sum of its proper divisors (298761).

21003003031 is a wasteful number, since it uses less digits than its factorization.

21003003031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 298760.

The product of its (nonzero) digits is 54, while the sum is 13.

Adding to 21003003031 its reverse (13030030012), we get a palindrome (34033033043).

The spelling of 21003003031 in words is "twenty-one billion, three million, three thousand, thirty-one".