21585958540 has 24 divisors (see below), whose sum is σ = 45839848320. Its totient is φ = 8537367168.

The previous prime is 21585958529. The next prime is 21585958547. The reversal of 21585958540 is 4585958512.

It is a hoax number, since the sum of its digits (52) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21585958547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6061692 + ... + 6065251.

It is an arithmetic number, because the mean of its divisors is an integer number (1909993680).

Almost surely, 2^21585958540 is an apocalyptic number.

21585958540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21585958540 is an abundant number, since it is smaller than the sum of its proper divisors (24253889780).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21585958540 is a wasteful number, since it uses less digits than its factorization.

21585958540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12127041 (or 12127039 counting only the distinct ones).

The product of its (nonzero) digits is 2880000, while the sum is 52.

The spelling of 21585958540 in words is "twenty-one billion, five hundred eighty-five million, nine hundred fifty-eight thousand, five hundred forty".