20423131421 has 32 divisors (see below), whose sum is σ = 26347708416. Its totient is φ = 15363432000.

The previous prime is 20423131403. The next prime is 20423131447. The reversal of 20423131421 is 12413132402.

It is not a de Polignac number, because 20423131421 - 2⁶ = 20423131357 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20423131481) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 994766 + ... + 1015088.

It is an arithmetic number, because the mean of its divisors is an integer number (823365888).

Almost surely, 2^20423131421 is an apocalyptic number.

It is an amenable number.

20423131421 is a deficient number, since it is larger than the sum of its proper divisors (5924576995).

20423131421 is a wasteful number, since it uses less digits than its factorization.

20423131421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20793.

The product of its (nonzero) digits is 1152, while the sum is 23.

Adding to 20423131421 its reverse (12413132402), we get a palindrome (32836263823).

The spelling of 20423131421 in words is "twenty billion, four hundred twenty-three million, one hundred thirty-one thousand, four hundred twenty-one".