21497103 has 8 divisors (see below), whose sum is σ = 31847600. Its totient is φ = 14331384.

The previous prime is 21497101. The next prime is 21497123. The reversal of 21497103 is 30179412.

It is not a de Polignac number, because 21497103 - 2¹ = 21497101 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 796189 = 21497103 / (2 + 1 + 4 + 9 + 7 + 1 + 0 + 3).

It is a Duffinian number.

It is a zygodrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21497101) 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, 398068 + ... + 398121.

It is an arithmetic number, because the mean of its divisors is an integer number (3980950).

Almost surely, 2^21497103 is an apocalyptic number.

21497103 is a deficient number, since it is larger than the sum of its proper divisors (10350497).

21497103 is an equidigital number, since it uses as much as digits as its factorization.

21497103 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 796198 (or 796192 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The square root of 21497103 is about 4636.4968456799. The cubic root of 21497103 is about 278.0523985561.

The spelling of 21497103 in words is "twenty-one million, four hundred ninety-seven thousand, one hundred three".