21102103639 has 2 divisors, whose sum is σ = 21102103640. Its totient is φ = 21102103638.

The previous prime is 21102103637. The next prime is 21102103661. The reversal of 21102103639 is 93630120112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21102103639 - 2¹ = 21102103637 is a prime.

It is a super-3 number, since 3×21102103639³ (a number of 32 digits) contains 333 as substring.

Together with 21102103637, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21102103637) 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, 10551051819 + 10551051820.

It is an arithmetic number, because the mean of its divisors is an integer number (10551051820).

Almost surely, 2^21102103639 is an apocalyptic number.

21102103639 is a deficient number, since it is larger than the sum of its proper divisors (1).

21102103639 is an equidigital number, since it uses as much as digits as its factorization.

21102103639 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1944, while the sum is 28.

The spelling of 21102103639 in words is "twenty-one billion, one hundred two million, one hundred three thousand, six hundred thirty-nine".