21584200645 has 16 divisors (see below), whose sum is σ = 29789739648. Its totient is φ = 14706319680.

The previous prime is 21584200619. The next prime is 21584200669. The reversal of 21584200645 is 54600248512.

It is not a de Polignac number, because 21584200645 - 2⁹ = 21584200133 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1958491 + ... + 1969480.

It is an arithmetic number, because the mean of its divisors is an integer number (1861858728).

Almost surely, 2^21584200645 is an apocalyptic number.

It is an amenable number.

21584200645 is a deficient number, since it is larger than the sum of its proper divisors (8205539003).

21584200645 is a wasteful number, since it uses less digits than its factorization.

21584200645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3928140.

The product of its (nonzero) digits is 76800, while the sum is 37.

The spelling of 21584200645 in words is "twenty-one billion, five hundred eighty-four million, two hundred thousand, six hundred forty-five".