21085041603 has 4 divisors (see below), whose sum is σ = 28113388808. Its totient is φ = 14056694400.

The previous prime is 21085041563. The next prime is 21085041661. The reversal of 21085041603 is 30614058012.

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

It is not a de Polignac number, because 21085041603 - 2¹⁰ = 21085040579 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21085041403) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3514173598 + ... + 3514173603.

It is an arithmetic number, because the mean of its divisors is an integer number (7028347202).

Almost surely, 2^21085041603 is an apocalyptic number.

21085041603 is a deficient number, since it is larger than the sum of its proper divisors (7028347205).

21085041603 is an equidigital number, since it uses as much as digits as its factorization.

21085041603 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7028347204.

The product of its (nonzero) digits is 5760, while the sum is 30.

Adding to 21085041603 its reverse (30614058012), we get a palindrome (51699099615).

The spelling of 21085041603 in words is "twenty-one billion, eighty-five million, forty-one thousand, six hundred three".