21102103 has 16 divisors (see below), whose sum is σ = 25021440. Its totient is φ = 17582400.

The previous prime is 21102101. The next prime is 21102113. The reversal of 21102103 is 30120112.

It is not a de Polignac number, because 21102103 - 2¹ = 21102101 is a prime.

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 21102103.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21102101) 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, 4851 + ... + 8107.

It is an arithmetic number, because the mean of its divisors is an integer number (1563840).

Almost surely, 2^21102103 is an apocalyptic number.

21102103 is a deficient number, since it is larger than the sum of its proper divisors (3919337).

21102103 is a wasteful number, since it uses less digits than its factorization.

21102103 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3318.

The product of its (nonzero) digits is 12, while the sum is 10.

The square root of 21102103 is about 4593.7025371698. The cubic root of 21102103 is about 276.3388289510.

Adding to 21102103 its reverse (30120112), we get a palindrome (51222215).

Subtracting 21102103 from its reverse (30120112), we obtain a square (9018009 = 3003²).

The spelling of 21102103 in words is "twenty-one million, one hundred two thousand, one hundred three".