20421120510023 has 4 divisors (see below), whose sum is σ = 21495916326360. Its totient is φ = 19346324693688.

The previous prime is 20421120510013. The next prime is 20421120510047. The reversal of 20421120510023 is 32001502112402.

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

It is a cyclic number.

It is not a de Polignac number, because 20421120510023 - 2³⁶ = 20352401033287 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20421120510013) 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, 537397908140 + ... + 537397908177.

It is an arithmetic number, because the mean of its divisors is an integer number (5373979081590).

Almost surely, 2^{20421120510023} is an apocalyptic number.

20421120510023 is a deficient number, since it is larger than the sum of its proper divisors (1074795816337).

20421120510023 is a wasteful number, since it uses less digits than its factorization.

20421120510023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1074795816336.

The product of its (nonzero) digits is 960, while the sum is 23.

Adding to 20421120510023 its reverse (32001502112402), we get a palindrome (52422622622425).

The spelling of 20421120510023 in words is "twenty trillion, four hundred twenty-one billion, one hundred twenty million, five hundred ten thousand, twenty-three".