21582342081 has 8 divisors (see below), whose sum is σ = 31973840160. Its totient is φ = 14388228036.

The previous prime is 21582342043. The next prime is 21582342083. The reversal of 21582342081 is 18024328512.

It is a happy number.

21582342081 is a `hidden beast` number, since 2 + 158 + 2 + 3 + 420 + 81 = 666.

It is not a de Polignac number, because 21582342081 - 2¹⁰ = 21582341057 is a prime.

It is a super-2 number, since 2×21582342081² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21582342083) 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, 399672975 + ... + 399673028.

It is an arithmetic number, because the mean of its divisors is an integer number (3996730020).

Almost surely, 2^21582342081 is an apocalyptic number.

It is an amenable number.

21582342081 is a deficient number, since it is larger than the sum of its proper divisors (10391498079).

21582342081 is an equidigital number, since it uses as much as digits as its factorization.

21582342081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 799346012 (or 799346006 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 36.

The spelling of 21582342081 in words is "twenty-one billion, five hundred eighty-two million, three hundred forty-two thousand, eighty-one".