21130030421 has 4 divisors (see below), whose sum is σ = 21160968192. Its totient is φ = 21099092652.

The previous prime is 21130030403. The next prime is 21130030429. The reversal of 21130030421 is 12403003112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21130030421 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 21130030421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21130030429) 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, 15467861 + ... + 15469226.

It is an arithmetic number, because the mean of its divisors is an integer number (5290242048).

Almost surely, 2^21130030421 is an apocalyptic number.

It is an amenable number.

21130030421 is a deficient number, since it is larger than the sum of its proper divisors (30937771).

21130030421 is an equidigital number, since it uses as much as digits as its factorization.

21130030421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30937770.

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 21130030421 its reverse (12403003112), we get a palindrome (33533033533).

The spelling of 21130030421 in words is "twenty-one billion, one hundred thirty million, thirty thousand, four hundred twenty-one".