20800510709 has 4 divisors (see below), whose sum is σ = 22691466240. Its totient is φ = 18909555180.

The previous prime is 20800510663. The next prime is 20800510721. The reversal of 20800510709 is 90701500802.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20800510709 - 2¹² = 20800506613 is a prime.

It is a super-2 number, since 2×20800510709² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20800510909) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 945477749 + ... + 945477770.

It is an arithmetic number, because the mean of its divisors is an integer number (5672866560).

Almost surely, 2^20800510709 is an apocalyptic number.

It is an amenable number.

20800510709 is a deficient number, since it is larger than the sum of its proper divisors (1890955531).

20800510709 is a wasteful number, since it uses less digits than its factorization.

20800510709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1890955530.

The product of its (nonzero) digits is 5040, while the sum is 32.

The spelling of 20800510709 in words is "twenty billion, eight hundred million, five hundred ten thousand, seven hundred nine".