20123310331021 has 4 divisors (see below), whose sum is σ = 20251484282332. Its totient is φ = 19995136379712.

The previous prime is 20123310330971. The next prime is 20123310331031. The reversal of 20123310331021 is 12013301332102.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 10515356222121 + 9607954108900 = 3242739^2 + 3099670^2 .

It is a cyclic number.

It is not a de Polignac number, because 20123310331021 - 2²³ = 20123301942413 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20123310330983 and 20123310331001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20123310331031) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64086975420 + ... + 64086975733.

It is an arithmetic number, because the mean of its divisors is an integer number (5062871070583).

Almost surely, 2^{20123310331021} is an apocalyptic number.

It is an amenable number.

20123310331021 is a deficient number, since it is larger than the sum of its proper divisors (128173951311).

20123310331021 is a wasteful number, since it uses less digits than its factorization.

20123310331021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128173951310.

The product of its (nonzero) digits is 648, while the sum is 22.

Adding to 20123310331021 its reverse (12013301332102), we get a palindrome (32136611663123).

The spelling of 20123310331021 in words is "twenty trillion, one hundred twenty-three billion, three hundred ten million, three hundred thirty-one thousand, twenty-one".