20847424081 has 24 divisors (see below), whose sum is σ = 23680520192. Its totient is φ = 18320385600.

The previous prime is 20847424067. The next prime is 20847424099. The reversal of 20847424081 is 18042474802.

It is not a de Polignac number, because 20847424081 - 2²⁵ = 20813869649 is a prime.

It is a super-2 number, since 2×20847424081² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20847424981) 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 23 ways as a sum of consecutive naturals, for example, 4074781 + ... + 4079893.

Almost surely, 2^20847424081 is an apocalyptic number.

It is an amenable number.

20847424081 is a deficient number, since it is larger than the sum of its proper divisors (2833096111).

20847424081 is a wasteful number, since it uses less digits than its factorization.

20847424081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6253 (or 6242 counting only the distinct ones).

The product of its (nonzero) digits is 114688, while the sum is 40.

Adding to 20847424081 its reverse (18042474802), we get a palindrome (38889898883).

The spelling of 20847424081 in words is "twenty billion, eight hundred forty-seven million, four hundred twenty-four thousand, eighty-one".