21231020013 has 16 divisors (see below), whose sum is σ = 32588181120. Its totient is φ = 12043454976.

The previous prime is 21231020009. The next prime is 21231020017. The reversal of 21231020013 is 31002013212.

It is an interprime number because it is at equal distance from previous prime (21231020009) and next prime (21231020017).

It is not a de Polignac number, because 21231020013 - 2² = 21231020009 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21231019974 and 21231020001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21231020017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3686908 + ... + 3692661.

It is an arithmetic number, because the mean of its divisors is an integer number (2036761320).

Almost surely, 2^21231020013 is an apocalyptic number.

It is an amenable number.

21231020013 is a deficient number, since it is larger than the sum of its proper divisors (11357161107).

21231020013 is a wasteful number, since it uses less digits than its factorization.

21231020013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7379716.

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21231020013 its reverse (31002013212), we get a palindrome (52233033225).

The spelling of 21231020013 in words is "twenty-one billion, two hundred thirty-one million, twenty thousand, thirteen".