21043511423 has 8 divisors (see below), whose sum is σ = 23041901520. Its totient is φ = 19059345280.

The previous prime is 21043511407. The next prime is 21043511443. The reversal of 21043511423 is 32411534012.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21043511423 - 2⁴ = 21043511407 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21043511392 and 21043511401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21043511443) 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 7 ways as a sum of consecutive naturals, for example, 3552890 + ... + 3558807.

It is an arithmetic number, because the mean of its divisors is an integer number (2880237690).

Almost surely, 2^21043511423 is an apocalyptic number.

21043511423 is a deficient number, since it is larger than the sum of its proper divisors (1998390097).

21043511423 is a wasteful number, since it uses less digits than its factorization.

21043511423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7111977.

The product of its (nonzero) digits is 2880, while the sum is 26.

The spelling of 21043511423 in words is "twenty-one billion, forty-three million, five hundred eleven thousand, four hundred twenty-three".