21000100103 has 16 divisors (see below), whose sum is σ = 21577713696. Its totient is φ = 20426757120.

The previous prime is 21000100097. The next prime is 21000100111. The reversal of 21000100103 is 30100100012.

It is a cyclic number.

It is not a de Polignac number, because 21000100103 - 2¹⁰ = 21000099079 is a prime.

It is a super-2 number, since 2×21000100103² (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 (21000100003) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17311925 + ... + 17313137.

It is an arithmetic number, because the mean of its divisors is an integer number (1348607106).

Almost surely, 2^21000100103 is an apocalyptic number.

21000100103 is a deficient number, since it is larger than the sum of its proper divisors (577613593).

21000100103 is a wasteful number, since it uses less digits than its factorization.

21000100103 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2594.

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

Adding to 21000100103 its reverse (30100100012), we get a palindrome (51100200115).

Subtracting 21000100103 from its reverse (30100100012), we obtain a palindrome (9099999909).

The spelling of 21000100103 in words is "twenty-one billion, one hundred thousand, one hundred three".