21043410451 has 32 divisors (see below), whose sum is σ = 25262341632. Its totient is φ = 17153959680.

The previous prime is 21043410449. The next prime is 21043410457. The reversal of 21043410451 is 15401434012.

It is a cyclic number.

It is not a de Polignac number, because 21043410451 - 2¹ = 21043410449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21043410457) 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 31 ways as a sum of consecutive naturals, for example, 2268615 + ... + 2277871.

It is an arithmetic number, because the mean of its divisors is an integer number (789448176).

Almost surely, 2^21043410451 is an apocalyptic number.

21043410451 is a deficient number, since it is larger than the sum of its proper divisors (4218931181).

21043410451 is a wasteful number, since it uses less digits than its factorization.

21043410451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9499.

The product of its (nonzero) digits is 1920, while the sum is 25.

Adding to 21043410451 its reverse (15401434012), we get a palindrome (36444844463).

The spelling of 21043410451 in words is "twenty-one billion, forty-three million, four hundred ten thousand, four hundred fifty-one".