21584064391 has 8 divisors (see below), whose sum is σ = 22736336000. Its totient is φ = 20433419640.

The previous prime is 21584064389. The next prime is 21584064413. The reversal of 21584064391 is 19346048512.

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

It is a cyclic number.

It is not a de Polignac number, because 21584064391 - 2¹ = 21584064389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21584064311) 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, 379425 + ... + 432586.

It is an arithmetic number, because the mean of its divisors is an integer number (2842042000).

Almost surely, 2^21584064391 is an apocalyptic number.

21584064391 is a deficient number, since it is larger than the sum of its proper divisors (1152271609).

21584064391 is a wasteful number, since it uses less digits than its factorization.

21584064391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 813429.

The product of its (nonzero) digits is 207360, while the sum is 43.

The spelling of 21584064391 in words is "twenty-one billion, five hundred eighty-four million, sixty-four thousand, three hundred ninety-one".