21101971139 has 2 divisors, whose sum is σ = 21101971140. Its totient is φ = 21101971138.

The previous prime is 21101971129. The next prime is 21101971141. The reversal of 21101971139 is 93117910112.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21101971139 is a prime.

Together with 21101971141, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21101971099 and 21101971108.

It is not a weakly prime, because it can be changed into another prime (21101971129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550985569 + 10550985570.

It is an arithmetic number, because the mean of its divisors is an integer number (10550985570).

Almost surely, 2^21101971139 is an apocalyptic number.

21101971139 is a deficient number, since it is larger than the sum of its proper divisors (1).

21101971139 is an equidigital number, since it uses as much as digits as its factorization.

21101971139 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3402, while the sum is 35.

The spelling of 21101971139 in words is "twenty-one billion, one hundred one million, nine hundred seventy-one thousand, one hundred thirty-nine".