21383616717 has 6 divisors (see below), whose sum is σ = 30887446382. Its totient is φ = 14255744472.

The previous prime is 21383616701. The next prime is 21383616721. The reversal of 21383616717 is 71761638312.

21383616717 is a `hidden beast` number, since 2 + 13 + 8 + 3 + 616 + 7 + 17 = 666.

It can be written as a sum of positive squares in only one way, i.e., 11946271401 + 9437345316 = 109299^2 + 97146^2 .

It is not a de Polignac number, because 21383616717 - 2⁴ = 21383616701 is a prime.

It is a super-3 number, since 3×21383616717³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21383616757) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1187978698 + ... + 1187978715.

Almost surely, 2^21383616717 is an apocalyptic number.

It is an amenable number.

21383616717 is a deficient number, since it is larger than the sum of its proper divisors (9503829665).

21383616717 is a wasteful number, since it uses less digits than its factorization.

21383616717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2375957419 (or 2375957416 counting only the distinct ones).

The product of its digits is 254016, while the sum is 45.

The spelling of 21383616717 in words is "twenty-one billion, three hundred eighty-three million, six hundred sixteen thousand, seven hundred seventeen".