21420030231 has 8 divisors (see below), whose sum is σ = 31733378160. Its totient is φ = 14280020136.

The previous prime is 21420030223. The next prime is 21420030239. The reversal of 21420030231 is 13203002412.

It is an interprime number because it is at equal distance from previous prime (21420030223) and next prime (21420030239).

It is not a de Polignac number, because 21420030231 - 2³ = 21420030223 is a prime.

It is a super-2 number, since 2×21420030231² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21420030239) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 396667200 + ... + 396667253.

It is an arithmetic number, because the mean of its divisors is an integer number (3966672270).

Almost surely, 2^21420030231 is an apocalyptic number.

21420030231 is a deficient number, since it is larger than the sum of its proper divisors (10313347929).

21420030231 is an equidigital number, since it uses as much as digits as its factorization.

21420030231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 793334462 (or 793334456 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

Adding to 21420030231 its reverse (13203002412), we get a palindrome (34623032643).

The spelling of 21420030231 in words is "twenty-one billion, four hundred twenty million, thirty thousand, two hundred thirty-one".