20013131021 has 8 divisors (see below), whose sum is σ = 22135105944. Its totient is φ = 17974370880.

The previous prime is 20013131011. The next prime is 20013131023. The reversal of 20013131021 is 12013131002.

It can be written as a sum of positive squares in 4 ways, for example, as 7421822500 + 12591308521 = 86150^2 + 112211^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20013131021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20013130987 and 20013131005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20013131023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20803190 + ... + 20804151.

It is an arithmetic number, because the mean of its divisors is an integer number (2766888243).

Almost surely, 2^20013131021 is an apocalyptic number.

It is an amenable number.

20013131021 is a deficient number, since it is larger than the sum of its proper divisors (2121974923).

20013131021 is a wasteful number, since it uses less digits than its factorization.

20013131021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41607391.

The product of its (nonzero) digits is 36, while the sum is 14.

Adding to 20013131021 its reverse (12013131002), we get a palindrome (32026262023).

The spelling of 20013131021 in words is "twenty billion, thirteen million, one hundred thirty-one thousand, twenty-one".