21100020003 has 6 divisors (see below), whose sum is σ = 30477806684. Its totient is φ = 14066679996.

The previous prime is 21100020001. The next prime is 21100020023. The reversal of 21100020003 is 30002000112.

It is a happy number.

It is not a de Polignac number, because 21100020003 - 2¹ = 21100020001 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9), and also a Moran number because the ratio is a prime number: 2344446667 = 21100020003 / (2 + 1 + 1 + 0 + 0 + 0 + 2 + 0 + 0 + 0 + 3).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21100020001) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1172223325 + ... + 1172223342.

Almost surely, 2^21100020003 is an apocalyptic number.

21100020003 is a deficient number, since it is larger than the sum of its proper divisors (9377786681).

21100020003 is a wasteful number, since it uses less digits than its factorization.

21100020003 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2344446673 (or 2344446670 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

Adding to 21100020003 its reverse (30002000112), we get a palindrome (51102020115).

The spelling of 21100020003 in words is "twenty-one billion, one hundred million, twenty thousand, three".