20643010081 has 16 divisors (see below), whose sum is σ = 21518848000. Its totient is φ = 19781269200.

The previous prime is 20643010079. The next prime is 20643010097. The reversal of 20643010081 is 18001034602.

It is a cyclic number.

It is not a de Polignac number, because 20643010081 - 2¹ = 20643010079 is a prime.

It is a super-2 number, since 2×20643010081² (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 (20643010051) 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 15 ways as a sum of consecutive naturals, for example, 1293730 + ... + 1309588.

It is an arithmetic number, because the mean of its divisors is an integer number (1344928000).

Almost surely, 2^20643010081 is an apocalyptic number.

It is an amenable number.

20643010081 is a deficient number, since it is larger than the sum of its proper divisors (875837919).

20643010081 is a wasteful number, since it uses less digits than its factorization.

20643010081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16300.

The product of its (nonzero) digits is 1152, while the sum is 25.

Adding to 20643010081 its reverse (18001034602), we get a palindrome (38644044683).

The spelling of 20643010081 in words is "twenty billion, six hundred forty-three million, ten thousand, eighty-one".