20644708609 has 8 divisors (see below), whose sum is σ = 24835739840. Its totient is φ = 16764124176.

The previous prime is 20644708603. The next prime is 20644708619. The reversal of 20644708609 is 90680744602.

It is a happy number.

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 20644708609 - 2⁵ = 20644708577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20644708603) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 77611554 + ... + 77611819.

It is an arithmetic number, because the mean of its divisors is an integer number (3104467480).

Almost surely, 2^20644708609 is an apocalyptic number.

It is an amenable number.

20644708609 is a deficient number, since it is larger than the sum of its proper divisors (4191031231).

20644708609 is a wasteful number, since it uses less digits than its factorization.

20644708609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155223399.

The product of its (nonzero) digits is 580608, while the sum is 46.

The spelling of 20644708609 in words is "twenty billion, six hundred forty-four million, seven hundred eight thousand, six hundred nine".