20420101243 has 4 divisors (see below), whose sum is σ = 20466616720. Its totient is φ = 20373585768.

The previous prime is 20420101183. The next prime is 20420101253. The reversal of 20420101243 is 34210102402.

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 20420101243 - 2¹³ = 20420093051 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20420101243.

It is not an unprimeable number, because it can be changed into a prime (20420101253) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23257080 + ... + 23257957.

It is an arithmetic number, because the mean of its divisors is an integer number (5116654180).

Almost surely, 2^20420101243 is an apocalyptic number.

20420101243 is a deficient number, since it is larger than the sum of its proper divisors (46515477).

20420101243 is an equidigital number, since it uses as much as digits as its factorization.

20420101243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46515476.

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

Adding to 20420101243 its reverse (34210102402), we get a palindrome (54630203645).

The spelling of 20420101243 in words is "twenty billion, four hundred twenty million, one hundred one thousand, two hundred forty-three".