21102718939 has 8 divisors (see below), whose sum is σ = 21825279360. Its totient is φ = 20382772800.

The previous prime is 21102718873. The next prime is 21102718963. The reversal of 21102718939 is 93981720112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-21102718939 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21102718895 and 21102718904.

It is not an unprimeable number, because it can be changed into a prime (21102718739) 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 in 7 ways as a sum of consecutive naturals, for example, 637144 + ... + 669445.

It is an arithmetic number, because the mean of its divisors is an integer number (2728159920).

Almost surely, 2^21102718939 is an apocalyptic number.

21102718939 is a deficient number, since it is larger than the sum of its proper divisors (722560421).

21102718939 is a wasteful number, since it uses less digits than its factorization.

21102718939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1307141.

The product of its (nonzero) digits is 54432, while the sum is 43.

The spelling of 21102718939 in words is "twenty-one billion, one hundred two million, seven hundred eighteen thousand, nine hundred thirty-nine".