20450243421 has 20 divisors (see below), whose sum is σ = 30564623232. Its totient is φ = 13626580968.

The previous prime is 20450243399. The next prime is 20450243423. The reversal of 20450243421 is 12434205402.

20450243421 is a `hidden beast` number, since 204 + 5 + 0 + 2 + 434 + 21 = 666.

It is not a de Polignac number, because 20450243421 - 2⁵ = 20450243389 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20450243423) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 99220 + ... + 225266.

Almost surely, 2^20450243421 is an apocalyptic number.

It is an amenable number.

20450243421 is a deficient number, since it is larger than the sum of its proper divisors (10114379811).

20450243421 is a wasteful number, since it uses less digits than its factorization.

20450243421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128062 (or 128053 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 27.

Adding to 20450243421 its reverse (12434205402), we get a palindrome (32884448823).

The spelling of 20450243421 in words is "twenty billion, four hundred fifty million, two hundred forty-three thousand, four hundred twenty-one".