21001000003 has 8 divisors (see below), whose sum is σ = 21680180096. Its totient is φ = 20321928000.

The previous prime is 21001000001. The next prime is 21001000019. The reversal of 21001000003 is 30000010012.

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 21001000003 - 2¹ = 21001000001 is a prime.

It is a super-2 number, since 2×21001000003² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21001000003.

It is not an unprimeable number, because it can be changed into a prime (21001000001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 596725 + ... + 630937.

It is an arithmetic number, because the mean of its divisors is an integer number (2710022512).

Almost surely, 2^21001000003 is an apocalyptic number.

21001000003 is a deficient number, since it is larger than the sum of its proper divisors (679180093).

21001000003 is a wasteful number, since it uses less digits than its factorization.

21001000003 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54045.

The product of its (nonzero) digits is 6, while the sum is 7.

Adding to 21001000003 its reverse (30000010012), we get a palindrome (51001010015).

The spelling of 21001000003 in words is "twenty-one billion, one million, three", and thus it is an aban number and an uban number.