20421435347 has 4 divisors (see below), whose sum is σ = 20482033416. Its totient is φ = 20360837280.

The previous prime is 20421435341. The next prime is 20421435401. The reversal of 20421435347 is 74353412402.

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

It is a cyclic number.

It is not a de Polignac number, because 20421435347 - 2¹⁰ = 20421434323 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20421435341) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30298529 + ... + 30299202.

It is an arithmetic number, because the mean of its divisors is an integer number (5120508354).

Almost surely, 2^20421435347 is an apocalyptic number.

20421435347 is a deficient number, since it is larger than the sum of its proper divisors (60598069).

20421435347 is an equidigital number, since it uses as much as digits as its factorization.

20421435347 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60598068.

The product of its (nonzero) digits is 80640, while the sum is 35.

Adding to 20421435347 its reverse (74353412402), we get a palindrome (94774847749).

The spelling of 20421435347 in words is "twenty billion, four hundred twenty-one million, four hundred thirty-five thousand, three hundred forty-seven".