21103475 has 6 divisors (see below), whose sum is σ = 26168340. Its totient is φ = 16882760.

The previous prime is 21103457. The next prime is 21103493. The reversal of 21103475 is 57430112.

It is an interprime number because it is at equal distance from previous prime (21103457) and next prime (21103493).

It is not a de Polignac number, because 21103475 - 2¹⁰ = 21102451 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21103475.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 422045 + ... + 422094.

It is an arithmetic number, because the mean of its divisors is an integer number (4361390).

Almost surely, 2^21103475 is an apocalyptic number.

21103475 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21103475 is a deficient number, since it is larger than the sum of its proper divisors (5064865).

21103475 is an equidigital number, since it uses as much as digits as its factorization.

21103475 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 844149 (or 844144 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 21103475 is about 4593.8518696188. The cubic root of 21103475 is about 276.3448177484.

Adding to 21103475 its reverse (57430112), we get a palindrome (78533587).

The spelling of 21103475 in words is "twenty-one million, one hundred three thousand, four hundred seventy-five".