21502605603 has 4 divisors (see below), whose sum is σ = 28670140808. Its totient is φ = 14335070400.

The previous prime is 21502605587. The next prime is 21502605629. The reversal of 21502605603 is 30650620512.

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

It is not a de Polignac number, because 21502605603 - 2⁴ = 21502605587 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21502605643) 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, 3583767598 + ... + 3583767603.

It is an arithmetic number, because the mean of its divisors is an integer number (7167535202).

Almost surely, 2^21502605603 is an apocalyptic number.

21502605603 is a deficient number, since it is larger than the sum of its proper divisors (7167535205).

21502605603 is an equidigital number, since it uses as much as digits as its factorization.

21502605603 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7167535204.

The product of its (nonzero) digits is 10800, while the sum is 30.

The spelling of 21502605603 in words is "twenty-one billion, five hundred two million, six hundred five thousand, six hundred three".