21879537677 has 2 divisors, whose sum is σ = 21879537678. Its totient is φ = 21879537676.

The previous prime is 21879537653. The next prime is 21879537679. The reversal of 21879537677 is 77673597812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17483715076 + 4395822601 = 132226^2 + 66301^2 .

It is a cyclic number.

It is not a de Polignac number, because 21879537677 - 2⁶ = 21879537613 is a prime.

Together with 21879537679, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21879537679) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10939768838 + 10939768839.

It is an arithmetic number, because the mean of its divisors is an integer number (10939768839).

Almost surely, 2^21879537677 is an apocalyptic number.

It is an amenable number.

21879537677 is a deficient number, since it is larger than the sum of its proper divisors (1).

21879537677 is an equidigital number, since it uses as much as digits as its factorization.

21879537677 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 31116960, while the sum is 62.

The spelling of 21879537677 in words is "twenty-one billion, eight hundred seventy-nine million, five hundred thirty-seven thousand, six hundred seventy-seven".