21130320421 has 12 divisors (see below), whose sum is σ = 24638856480. Its totient is φ = 18068459640.

The previous prime is 21130320401. The next prime is 21130320433. The reversal of 21130320421 is 12402303112.

It is a happy number.

It is not a de Polignac number, because 21130320421 - 2⁵ = 21130320389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21130320401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 494065 + ... + 535126.

It is an arithmetic number, because the mean of its divisors is an integer number (2053238040).

Almost surely, 2^21130320421 is an apocalyptic number.

It is an amenable number.

21130320421 is a deficient number, since it is larger than the sum of its proper divisors (3508536059).

21130320421 is a wasteful number, since it uses less digits than its factorization.

21130320421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1029624 (or 1029617 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21130320421 its reverse (12402303112), we get a palindrome (33532623533).

It can be divided in two parts, 21130 and 320421, that added together give a triangular number (341551 = T₈₂₆).

The spelling of 21130320421 in words is "twenty-one billion, one hundred thirty million, three hundred twenty thousand, four hundred twenty-one".