21402124203 has 4 divisors (see below), whose sum is σ = 28536165608. Its totient is φ = 14268082800.

The previous prime is 21402124187. The next prime is 21402124223. The reversal of 21402124203 is 30242120412.

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

It is not a de Polignac number, because 21402124203 - 2⁴ = 21402124187 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 21402124203.

It is not an unprimeable number, because it can be changed into a prime (21402124223) 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, 3567020698 + ... + 3567020703.

It is an arithmetic number, because the mean of its divisors is an integer number (7134041402).

Almost surely, 2^21402124203 is an apocalyptic number.

21402124203 is a deficient number, since it is larger than the sum of its proper divisors (7134041405).

21402124203 is an equidigital number, since it uses as much as digits as its factorization.

21402124203 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7134041404.

The product of its (nonzero) digits is 768, while the sum is 21.

Adding to 21402124203 its reverse (30242120412), we get a palindrome (51644244615).

The spelling of 21402124203 in words is "twenty-one billion, four hundred two million, one hundred twenty-four thousand, two hundred three".