21809585358 has 24 divisors (see below), whose sum is σ = 51549929496. Its totient is φ = 6608965200.

The previous prime is 21809585353. The next prime is 21809585381. The reversal of 21809585358 is 85358590812.

It is a happy number.

21809585358 is a `hidden beast` number, since 2 + 1 + 8 + 0 + 9 + 585 + 3 + 58 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21809585353) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 55074513 + ... + 55074908.

It is an arithmetic number, because the mean of its divisors is an integer number (2147913729).

Almost surely, 2^21809585358 is an apocalyptic number.

21809585358 is an abundant number, since it is smaller than the sum of its proper divisors (29740344138).

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

21809585358 is a wasteful number, since it uses less digits than its factorization.

21809585358 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110149440 (or 110149437 counting only the distinct ones).

The product of its (nonzero) digits is 3456000, while the sum is 54.

The spelling of 21809585358 in words is "twenty-one billion, eight hundred nine million, five hundred eighty-five thousand, three hundred fifty-eight".