21665893938139 has 8 divisors (see below), whose sum is σ = 24081473880432. Its totient is φ = 19324639532640.

The previous prime is 21665893938131. The next prime is 21665893938181. The reversal of 21665893938139 is 93183939856612.

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

It is a cyclic number.

It is not a de Polignac number, because 21665893938139 - 2³ = 21665893938131 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21665893938131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18581383584 + ... + 18581384749.

It is an arithmetic number, because the mean of its divisors is an integer number (3010184235054).

Almost surely, 2^{21665893938139} is an apocalyptic number.

21665893938139 is a deficient number, since it is larger than the sum of its proper divisors (2415579942293).

21665893938139 is a wasteful number, since it uses less digits than its factorization.

21665893938139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37162768397.

The product of its digits is 453496320, while the sum is 73.

The spelling of 21665893938139 in words is "twenty-one trillion, six hundred sixty-five billion, eight hundred ninety-three million, nine hundred thirty-eight thousand, one hundred thirty-nine".