21003543115 has 4 divisors (see below), whose sum is σ = 25204251744. Its totient is φ = 16802834488.

The previous prime is 21003543109. The next prime is 21003543149. The reversal of 21003543115 is 51134530012.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21003543115 - 2¹¹ = 21003541067 is a prime.

It is a super-2 number, since 2×21003543115² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21003543115.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 2100354307 + ... + 2100354316.

It is an arithmetic number, because the mean of its divisors is an integer number (6301062936).

Almost surely, 2^21003543115 is an apocalyptic number.

21003543115 is a deficient number, since it is larger than the sum of its proper divisors (4200708629).

21003543115 is an equidigital number, since it uses as much as digits as its factorization.

21003543115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4200708628.

The product of its (nonzero) digits is 1800, while the sum is 25.

The spelling of 21003543115 in words is "twenty-one billion, three million, five hundred forty-three thousand, one hundred fifteen".