21603041 has 4 divisors (see below), whose sum is σ = 21661332. Its totient is φ = 21544752.

The previous prime is 21603017. The next prime is 21603047. The reversal of 21603041 is 14030612.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 12988816 + 8614225 = 3604^2 + 2935^2 .

It is a cyclic number.

It is not a de Polignac number, because 21603041 - 2¹⁴ = 21586657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21603047) 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 3 ways as a sum of consecutive naturals, for example, 28586 + ... + 29331.

It is an arithmetic number, because the mean of its divisors is an integer number (5415333).

Almost surely, 2^21603041 is an apocalyptic number.

It is an amenable number.

21603041 is a deficient number, since it is larger than the sum of its proper divisors (58291).

21603041 is an equidigital number, since it uses as much as digits as its factorization.

21603041 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58290.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 21603041 is about 4647.9071634446. The cubic root of 21603041 is about 278.5083989143.

Adding to 21603041 its reverse (14030612), we get a palindrome (35633653).

The spelling of 21603041 in words is "twenty-one million, six hundred three thousand, forty-one".