20717909679 has 16 divisors (see below), whose sum is σ = 28278277632. Its totient is φ = 13485013248.

The previous prime is 20717909671. The next prime is 20717909687. The reversal of 20717909679 is 97690971702.

It is an interprime number because it is at equal distance from previous prime (20717909671) and next prime (20717909687).

It is not a de Polignac number, because 20717909679 - 2³ = 20717909671 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20717909671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 282847 + ... + 348479.

It is an arithmetic number, because the mean of its divisors is an integer number (1767392352).

Almost surely, 2^20717909679 is an apocalyptic number.

20717909679 is a deficient number, since it is larger than the sum of its proper divisors (7560367953).

20717909679 is a wasteful number, since it uses less digits than its factorization.

20717909679 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68126.

The product of its (nonzero) digits is 3000564, while the sum is 57.

The spelling of 20717909679 in words is "twenty billion, seven hundred seventeen million, nine hundred nine thousand, six hundred seventy-nine".