21403220403 has 4 divisors (see below), whose sum is σ = 28537627208. Its totient is φ = 14268813600.

The previous prime is 21403220387. The next prime is 21403220411. The reversal of 21403220403 is 30402230412.

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

It is not a de Polignac number, because 21403220403 - 2⁴ = 21403220387 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21403220403.

It is not an unprimeable number, because it can be changed into a prime (21403220903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3567203398 + ... + 3567203403.

It is an arithmetic number, because the mean of its divisors is an integer number (7134406802).

Almost surely, 2^21403220403 is an apocalyptic number.

21403220403 is a deficient number, since it is larger than the sum of its proper divisors (7134406805).

21403220403 is an equidigital number, since it uses as much as digits as its factorization.

21403220403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7134406804.

The product of its (nonzero) digits is 1152, while the sum is 21.

Adding to 21403220403 its reverse (30402230412), we get a palindrome (51805450815).

The spelling of 21403220403 in words is "twenty-one billion, four hundred three million, two hundred twenty thousand, four hundred three".