21584787841 has 16 divisors (see below), whose sum is σ = 22915676160. Its totient is φ = 20299648320.

The previous prime is 21584787803. The next prime is 21584787857. The reversal of 21584787841 is 14878748512.

It is a de Polignac number, because none of the positive numbers 2^k-21584787841 is a prime.

It is a super-2 number, since 2×21584787841² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21584787941) 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, 122976 + ... + 241438.

It is an arithmetic number, because the mean of its divisors is an integer number (1432229760).

Almost surely, 2^21584787841 is an apocalyptic number.

It is an amenable number.

21584787841 is a deficient number, since it is larger than the sum of its proper divisors (1330888319).

21584787841 is a wasteful number, since it uses less digits than its factorization.

21584787841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118656.

The product of its digits is 4014080, while the sum is 55.

The spelling of 21584787841 in words is "twenty-one billion, five hundred eighty-four million, seven hundred eighty-seven thousand, eight hundred forty-one".