20031320021 has 8 divisors (see below), whose sum is σ = 20638508184. Its totient is φ = 19429780480.

The previous prime is 20031319937. The next prime is 20031320051. The reversal of 20031320021 is 12002313002.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 579121 + 20030740900 = 761^2 + 141530^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 20031320021 - 2¹⁰ = 20031318997 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20031319978 and 20031320005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20031320051) 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, 1404956 + ... + 1419141.

It is an arithmetic number, because the mean of its divisors is an integer number (2579813523).

Almost surely, 2^20031320021 is an apocalyptic number.

It is an amenable number.

20031320021 is a deficient number, since it is larger than the sum of its proper divisors (607188163).

20031320021 is a wasteful number, since it uses less digits than its factorization.

20031320021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2824311.

The product of its (nonzero) digits is 72, while the sum is 14.

Adding to 20031320021 its reverse (12002313002), we get a palindrome (32033633023).

The spelling of 20031320021 in words is "twenty billion, thirty-one million, three hundred twenty thousand, twenty-one".