20523123121 has 8 divisors (see below), whose sum is σ = 20756601000. Its totient is φ = 20289709440.

The previous prime is 20523123113. The next prime is 20523123143. The reversal of 20523123121 is 12132132502.

It can be written as a sum of positive squares in 4 ways, for example, as 1799032225 + 18724090896 = 42415^2 + 136836^2 .

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 20523123121 - 2³ = 20523123113 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20523123092 and 20523123101.

It is not an unprimeable number, because it can be changed into a prime (20523123191) 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, 963931 + ... + 984991.

It is an arithmetic number, because the mean of its divisors is an integer number (2594575125).

Almost surely, 2^20523123121 is an apocalyptic number.

It is an amenable number.

20523123121 is a deficient number, since it is larger than the sum of its proper divisors (233477879).

20523123121 is a wasteful number, since it uses less digits than its factorization.

20523123121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32099.

The product of its (nonzero) digits is 720, while the sum is 22.

Adding to 20523123121 its reverse (12132132502), we get a palindrome (32655255623).

The spelling of 20523123121 in words is "twenty billion, five hundred twenty-three million, one hundred twenty-three thousand, one hundred twenty-one".