20654432665 has 8 divisors (see below), whose sum is σ = 24805493640. Its totient is φ = 16510096512.

The previous prime is 20654432647. The next prime is 20654432717. The reversal of 20654432665 is 56623445602.

It can be written as a sum of positive squares in 4 ways, for example, as 8864599104 + 11789833561 = 94152^2 + 108581^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20654432665 - 2⁹ = 20654432153 is a prime.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 1674444 + ... + 1686733.

It is an arithmetic number, because the mean of its divisors is an integer number (3100686705).

Almost surely, 2^20654432665 is an apocalyptic number.

It is an amenable number.

20654432665 is a deficient number, since it is larger than the sum of its proper divisors (4151060975).

20654432665 is a wasteful number, since it uses less digits than its factorization.

20654432665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3362411.

The product of its (nonzero) digits is 1036800, while the sum is 43.

The spelling of 20654432665 in words is "twenty billion, six hundred fifty-four million, four hundred thirty-two thousand, six hundred sixty-five".