20340120421 has 4 divisors (see below), whose sum is σ = 20723896332. Its totient is φ = 19956344512.

The previous prime is 20340120413. The next prime is 20340120433. The reversal of 20340120421 is 12402104302.

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

It can be written as a sum of positive squares in 2 ways, for example, as 5619151521 + 14720968900 = 74961^2 + 121330^2 .

It is a cyclic number.

It is not a de Polignac number, because 20340120421 - 2³ = 20340120413 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 (20340120401) 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, 191887876 + ... + 191887981.

It is an arithmetic number, because the mean of its divisors is an integer number (5180974083).

Almost surely, 2^20340120421 is an apocalyptic number.

It is an amenable number.

20340120421 is a deficient number, since it is larger than the sum of its proper divisors (383775911).

20340120421 is an equidigital number, since it uses as much as digits as its factorization.

20340120421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 383775910.

The product of its (nonzero) digits is 384, while the sum is 19.

Adding to 20340120421 its reverse (12402104302), we get a palindrome (32742224723).

The spelling of 20340120421 in words is "twenty billion, three hundred forty million, one hundred twenty thousand, four hundred twenty-one".