20805842423 has 4 divisors (see below), whose sum is σ = 21158483880. Its totient is φ = 20453200968.

The previous prime is 20805842303. The next prime is 20805842459. The reversal of 20805842423 is 32424850802.

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 20805842423 - 2¹² = 20805838327 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 (20805848423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 176320640 + ... + 176320757.

It is an arithmetic number, because the mean of its divisors is an integer number (5289620970).

Almost surely, 2^20805842423 is an apocalyptic number.

20805842423 is a deficient number, since it is larger than the sum of its proper divisors (352641457).

20805842423 is an equidigital number, since it uses as much as digits as its factorization.

20805842423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 352641456.

The product of its (nonzero) digits is 122880, while the sum is 38.

The spelling of 20805842423 in words is "twenty billion, eight hundred five million, eight hundred forty-two thousand, four hundred twenty-three".