20423843777 has 4 divisors (see below), whose sum is σ = 20424460116. Its totient is φ = 20423227440.

The previous prime is 20423843767. The next prime is 20423843813. The reversal of 20423843777 is 77734832402.

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 7041055921 + 13382787856 = 83911^2 + 115684^2 .

It is a cyclic number.

It is not a de Polignac number, because 20423843777 - 2¹⁰ = 20423842753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20423843767) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 255458 + ... + 325739.

It is an arithmetic number, because the mean of its divisors is an integer number (5106115029).

Almost surely, 2^20423843777 is an apocalyptic number.

It is an amenable number.

20423843777 is a deficient number, since it is larger than the sum of its proper divisors (616339).

20423843777 is an equidigital number, since it uses as much as digits as its factorization.

20423843777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 616338.

The product of its (nonzero) digits is 1580544, while the sum is 47.

The spelling of 20423843777 in words is "twenty billion, four hundred twenty-three million, eight hundred forty-three thousand, seven hundred seventy-seven".