20665084799645 has 64 divisors (see below), whose sum is σ = 29307009634560. Its totient is φ = 13790645299200.

The previous prime is 20665084799633. The next prime is 20665084799659. The reversal of 20665084799645 is 54699748056602.

It is a happy number.

It is not a de Polignac number, because 20665084799645 - 2¹⁰ = 20665084798621 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 84060647 + ... + 84306123.

It is an arithmetic number, because the mean of its divisors is an integer number (457922025540).

Almost surely, 2^{20665084799645} is an apocalyptic number.

It is an amenable number.

20665084799645 is a deficient number, since it is larger than the sum of its proper divisors (8641924834915).

20665084799645 is a wasteful number, since it uses less digits than its factorization.

20665084799645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 246206.

The product of its (nonzero) digits is 783820800, while the sum is 71.

The spelling of 20665084799645 in words is "twenty trillion, six hundred sixty-five billion, eighty-four million, seven hundred ninety-nine thousand, six hundred forty-five".