21080603 has 6 divisors (see below), whose sum is σ = 21264156. Its totient is φ = 20898612.

The previous prime is 21080599. The next prime is 21080611. The reversal of 21080603 is 30608012.

It is not a de Polignac number, because 21080603 - 2² = 21080599 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21080623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 15476 + ... + 16782.

It is an arithmetic number, because the mean of its divisors is an integer number (3544026).

Almost surely, 2^21080603 is an apocalyptic number.

21080603 is a deficient number, since it is larger than the sum of its proper divisors (183553).

21080603 is an equidigital number, since it uses as much as digits as its factorization.

21080603 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1561 (or 1434 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 21080603 is about 4591.3617805614. The cubic root of 21080603 is about 276.2449472537.

Adding to 21080603 its reverse (30608012), we get a palindrome (51688615).

The spelling of 21080603 in words is "twenty-one million, eighty thousand, six hundred three".