20646304645 has 4 divisors (see below), whose sum is σ = 24775565580. Its totient is φ = 16517043712.

The previous prime is 20646304559. The next prime is 20646304673. The reversal of 20646304645 is 54640364602.

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 14743302084 + 5903002561 = 121422^2 + 76831^2 .

It is a cyclic number.

It is not a de Polignac number, because 20646304645 - 2¹⁷ = 20646173573 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20646304598 and 20646304607.

It is a congruent number.

It is an unprimeable number.

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, 2064630460 + ... + 2064630469.

It is an arithmetic number, because the mean of its divisors is an integer number (6193891395).

Almost surely, 2^20646304645 is an apocalyptic number.

It is an amenable number.

20646304645 is a deficient number, since it is larger than the sum of its proper divisors (4129260935).

20646304645 is an equidigital number, since it uses as much as digits as its factorization.

20646304645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4129260934.

The product of its (nonzero) digits is 414720, while the sum is 40.

The spelling of 20646304645 in words is "twenty billion, six hundred forty-six million, three hundred four thousand, six hundred forty-five".