21383682731 has 8 divisors (see below), whose sum is σ = 22054883904. Its totient is φ = 20721491200.

The previous prime is 21383682709. The next prime is 21383682767. The reversal of 21383682731 is 13728638312.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21383682731 is a prime.

It is a super-3 number, since 3×21383682731³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21383082731) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2247590 + ... + 2257083.

It is an arithmetic number, because the mean of its divisors is an integer number (2756860488).

Almost surely, 2^21383682731 is an apocalyptic number.

21383682731 is a deficient number, since it is larger than the sum of its proper divisors (671201173).

21383682731 is a wasteful number, since it uses less digits than its factorization.

21383682731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4504821.

The product of its digits is 290304, while the sum is 44.

The spelling of 21383682731 in words is "twenty-one billion, three hundred eighty-three million, six hundred eighty-two thousand, seven hundred thirty-one".