20979758709 has 144 divisors (see below), whose sum is σ = 38866481472. Its totient is φ = 10806276096.

The previous prime is 20979758707. The next prime is 20979758711. The reversal of 20979758709 is 90785797902.

It is an interprime number because it is at equal distance from previous prime (20979758707) and next prime (20979758711).

It is not a de Polignac number, because 20979758709 - 2¹ = 20979758707 is a prime.

It is a super-2 number, since 2×20979758709² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (63) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20979758707) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 74133282 + ... + 74133564.

Almost surely, 2^20979758709 is an apocalyptic number.

It is an amenable number.

20979758709 is a deficient number, since it is larger than the sum of its proper divisors (17886722763).

20979758709 is a wasteful number, since it uses less digits than its factorization.

20979758709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 576 (or 566 counting only the distinct ones).

The product of its (nonzero) digits is 20003760, while the sum is 63.

The spelling of 20979758709 in words is "twenty billion, nine hundred seventy-nine million, seven hundred fifty-eight thousand, seven hundred nine".