21103591203 has 20 divisors (see below), whose sum is σ = 31683559600. Its totient is φ = 13998351312.

The previous prime is 21103591193. The next prime is 21103591241. The reversal of 21103591203 is 30219530112.

It is not a de Polignac number, because 21103591203 - 2²⁴ = 21086813987 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21103591273) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 638500 + ... + 670737.

It is an arithmetic number, because the mean of its divisors is an integer number (1584177980).

Almost surely, 2^21103591203 is an apocalyptic number.

21103591203 is a deficient number, since it is larger than the sum of its proper divisors (10579968397).

21103591203 is a wasteful number, since it uses less digits than its factorization.

21103591203 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1309448 (or 1309439 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 27.

The spelling of 21103591203 in words is "twenty-one billion, one hundred three million, five hundred ninety-one thousand, two hundred three".