21847846585 has 4 divisors (see below), whose sum is σ = 26217415908. Its totient is φ = 17478277264.

The previous prime is 21847846583. The next prime is 21847846589. The reversal of 21847846585 is 58564874812.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13624258729 + 8223587856 = 116723^2 + 90684^2 .

It is a cyclic number.

It is not a de Polignac number, because 21847846585 - 2¹ = 21847846583 is a prime.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21847846583) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2184784654 + ... + 2184784663.

It is an arithmetic number, because the mean of its divisors is an integer number (6554353977).

Almost surely, 2^21847846585 is an apocalyptic number.

It is an amenable number.

21847846585 is a deficient number, since it is larger than the sum of its proper divisors (4369569323).

21847846585 is an equidigital number, since it uses as much as digits as its factorization.

21847846585 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4369569322.

The product of its digits is 17203200, while the sum is 58.

The spelling of 21847846585 in words is "twenty-one billion, eight hundred forty-seven million, eight hundred forty-six thousand, five hundred eighty-five".