21584243684 has 12 divisors (see below), whose sum is σ = 37867573884. Its totient is φ = 10764936864.

The previous prime is 21584243641. The next prime is 21584243719. The reversal of 21584243684 is 48634248512.

It can be written as a sum of positive squares in 2 ways, for example, as 18953579584 + 2630664100 = 137672^2 + 51290^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6794459 + ... + 6797634.

It is an arithmetic number, because the mean of its divisors is an integer number (3155631157).

Almost surely, 2^21584243684 is an apocalyptic number.

It is an amenable number.

21584243684 is a deficient number, since it is larger than the sum of its proper divisors (16283330200).

21584243684 is a wasteful number, since it uses less digits than its factorization.

21584243684 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13592494 (or 13592492 counting only the distinct ones).

The product of its digits is 1474560, while the sum is 47.

The spelling of 21584243684 in words is "twenty-one billion, five hundred eighty-four million, two hundred forty-three thousand, six hundred eighty-four".