20423423421 has 24 divisors (see below), whose sum is σ = 30423107520. Its totient is φ = 13196299200.

The previous prime is 20423423401. The next prime is 20423423477. The reversal of 20423423421 is 12432432402.

20423423421 is a `hidden beast` number, since 2 + 0 + 4 + 234 + 2 + 3 + 421 = 666.

It is not a de Polignac number, because 20423423421 - 2⁵ = 20423423389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20423423401) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 233160 + ... + 308561.

It is an arithmetic number, because the mean of its divisors is an integer number (1267629480).

Almost surely, 2^20423423421 is an apocalyptic number.

It is an amenable number.

20423423421 is a deficient number, since it is larger than the sum of its proper divisors (9999684099).

20423423421 is a wasteful number, since it uses less digits than its factorization.

20423423421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 541857 (or 541854 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 27.

Adding to 20423423421 its reverse (12432432402), we get a palindrome (32855855823).

The spelling of 20423423421 in words is "twenty billion, four hundred twenty-three million, four hundred twenty-three thousand, four hundred twenty-one".