21010113421 has 6 divisors (see below), whose sum is σ = 23093761166. Its totient is φ = 19100103000.

The previous prime is 21010113413. The next prime is 21010113463. The reversal of 21010113421 is 12431101012.

It can be written as a sum of positive squares in only one way, i.e., 19902155625 + 1107957796 = 141075^2 + 33286^2 .

It is not a de Polignac number, because 21010113421 - 2³ = 21010113413 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21010113395 and 21010113404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21010113491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 86818530 + ... + 86818771.

Almost surely, 2^21010113421 is an apocalyptic number.

It is an amenable number.

21010113421 is a deficient number, since it is larger than the sum of its proper divisors (2083647745).

21010113421 is a wasteful number, since it uses less digits than its factorization.

21010113421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173637323 (or 173637312 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 21010113421 its reverse (12431101012), we get a palindrome (33441214433).

It can be divided in two parts, 21010 and 113421, that added together give a palindrome (134431).

The spelling of 21010113421 in words is "twenty-one billion, ten million, one hundred thirteen thousand, four hundred twenty-one".