21082717585 has 16 divisors (see below), whose sum is σ = 27788664960. Its totient is φ = 15283762560.

The previous prime is 21082717577. The next prime is 21082717589. The reversal of 21082717585 is 58571728012.

It is not a de Polignac number, because 21082717585 - 2³ = 21082717577 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21082717589) 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, 4822236 + ... + 4826605.

It is an arithmetic number, because the mean of its divisors is an integer number (1736791560).

Almost surely, 2^21082717585 is an apocalyptic number.

It is an amenable number.

21082717585 is a deficient number, since it is larger than the sum of its proper divisors (6705947375).

21082717585 is a wasteful number, since it uses less digits than its factorization.

21082717585 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9648888.

The product of its (nonzero) digits is 313600, while the sum is 46.

The spelling of 21082717585 in words is "twenty-one billion, eighty-two million, seven hundred seventeen thousand, five hundred eighty-five".