20423120421 has 8 divisors (see below), whose sum is σ = 29706357024. Its totient is φ = 12377648720.

The previous prime is 20423120381. The next prime is 20423120423. The reversal of 20423120421 is 12402132402.

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 20423120421 - 2⁹ = 20423119909 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20423120423) 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, 309441186 + ... + 309441251.

It is an arithmetic number, because the mean of its divisors is an integer number (3713294628).

Almost surely, 2^20423120421 is an apocalyptic number.

It is an amenable number.

20423120421 is a deficient number, since it is larger than the sum of its proper divisors (9283236603).

20423120421 is a wasteful number, since it uses less digits than its factorization.

20423120421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 618882451.

The product of its (nonzero) digits is 768, while the sum is 21.

Adding to 20423120421 its reverse (12402132402), we get a palindrome (32825252823).

The spelling of 20423120421 in words is "twenty billion, four hundred twenty-three million, one hundred twenty thousand, four hundred twenty-one".