20979879671 has 2 divisors, whose sum is σ = 20979879672. Its totient is φ = 20979879670.

The previous prime is 20979879649. The next prime is 20979879677. The reversal of 20979879671 is 17697897902.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20979879671 - 2⁶ = 20979879607 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20979879598 and 20979879607.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20979879677) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10489939835 + 10489939836.

It is an arithmetic number, because the mean of its divisors is an integer number (10489939836).

Almost surely, 2^20979879671 is an apocalyptic number.

20979879671 is a deficient number, since it is larger than the sum of its proper divisors (1).

20979879671 is an equidigital number, since it uses as much as digits as its factorization.

20979879671 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24004512, while the sum is 65.

The spelling of 20979879671 in words is "twenty billion, nine hundred seventy-nine million, eight hundred seventy-nine thousand, six hundred seventy-one".