21647865347 has 16 divisors (see below), whose sum is σ = 22878332928. Its totient is φ = 20451191040.

The previous prime is 21647865341. The next prime is 21647865361. The reversal of 21647865347 is 74356874612.

It is a de Polignac number, because none of the positive numbers 2^k-21647865347 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21647865341) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3453338 + ... + 3459600.

It is an arithmetic number, because the mean of its divisors is an integer number (1429895808).

Almost surely, 2^21647865347 is an apocalyptic number.

21647865347 is a deficient number, since it is larger than the sum of its proper divisors (1230467581).

21647865347 is a wasteful number, since it uses less digits than its factorization.

21647865347 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8930.

The product of its digits is 6773760, while the sum is 53.

The spelling of 21647865347 in words is "twenty-one billion, six hundred forty-seven million, eight hundred sixty-five thousand, three hundred forty-seven".