21010001003 has 6 divisors (see below), whose sum is σ = 21248728884. Its totient is φ = 20773925744.

The previous prime is 21010000967. The next prime is 21010001011. The reversal of 21010001003 is 30010001012.

It is not a de Polignac number, because 21010001003 - 2¹⁶ = 21009935467 is a prime.

It is a super-2 number, since 2×21010001003² (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 (21010001063) 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 5 ways as a sum of consecutive naturals, for example, 1318301 + ... + 1334142.

It is an arithmetic number, because the mean of its divisors is an integer number (3541454814).

Almost surely, 2^21010001003 is an apocalyptic number.

21010001003 is a deficient number, since it is larger than the sum of its proper divisors (238727881).

21010001003 is an frugal number, since it uses more digits than its factorization.

21010001003 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2652621 (or 2652532 counting only the distinct ones).

The product of its (nonzero) digits is 6, while the sum is 8.

Adding to 21010001003 its reverse (30010001012), we get a palindrome (51020002015).

Subtracting 21010001003 from its reverse (30010001012), we obtain a palindrome (9000000009).

The spelling of 21010001003 in words is "twenty-one billion, ten million, one thousand, three".