20688912709 has 8 divisors (see below), whose sum is σ = 21050107520. Its totient is φ = 20330200800.

The previous prime is 20688912703. The next prime is 20688912757. The reversal of 20688912709 is 90721988602.

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 20688912709 - 2²³ = 20680524101 is a prime.

It is a super-2 number, since 2×20688912709² (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 (20688912703) 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, 603912 + ... + 637249.

It is an arithmetic number, because the mean of its divisors is an integer number (2631263440).

Almost surely, 2^20688912709 is an apocalyptic number.

It is an amenable number.

20688912709 is a deficient number, since it is larger than the sum of its proper divisors (361194811).

20688912709 is a wasteful number, since it uses less digits than its factorization.

20688912709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1241451.

The product of its (nonzero) digits is 870912, while the sum is 52.

The spelling of 20688912709 in words is "twenty billion, six hundred eighty-eight million, nine hundred twelve thousand, seven hundred nine".