21642543444463 has 4 divisors (see below), whose sum is σ = 21642675992008. Its totient is φ = 21642410896920.

The previous prime is 21642543444451. The next prime is 21642543444497. The reversal of 21642543444463 is 36444434524612.

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 21642543444463 - 2³³ = 21633953509871 is a prime.

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 21642543444463.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21642543444563) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66028548 + ... + 66355513.

It is an arithmetic number, because the mean of its divisors is an integer number (5410668998002).

Almost surely, 2^{21642543444463} is an apocalyptic number.

21642543444463 is a deficient number, since it is larger than the sum of its proper divisors (132547545).

21642543444463 is a wasteful number, since it uses less digits than its factorization.

21642543444463 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132547544.

The product of its digits is 26542080, while the sum is 52.

The spelling of 21642543444463 in words is "twenty-one trillion, six hundred forty-two billion, five hundred forty-three million, four hundred forty-four thousand, four hundred sixty-three".