20001215543 has 16 divisors (see below), whose sum is σ = 20283086880. Its totient is φ = 19721856000.

The previous prime is 20001215539. The next prime is 20001215567. The reversal of 20001215543 is 34551210002.

It is a cyclic number.

It is not a de Polignac number, because 20001215543 - 2² = 20001215539 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20001215573) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15662021 + ... + 15663297.

It is an arithmetic number, because the mean of its divisors is an integer number (1267692930).

Almost surely, 2^20001215543 is an apocalyptic number.

20001215543 is a deficient number, since it is larger than the sum of its proper divisors (281871337).

20001215543 is a wasteful number, since it uses less digits than its factorization.

20001215543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2098.

The product of its (nonzero) digits is 1200, while the sum is 23.

Adding to 20001215543 its reverse (34551210002), we get a palindrome (54552425545).

The spelling of 20001215543 in words is "twenty billion, one million, two hundred fifteen thousand, five hundred forty-three".