21716666443 has 4 divisors (see below), whose sum is σ = 22465517040. Its totient is φ = 20967815848.

The previous prime is 21716666429. The next prime is 21716666453. The reversal of 21716666443 is 34466661712.

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 21716666443 - 2²⁹ = 21179795531 is a prime.

It is a super-2 number, since 2×21716666443² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21716666393 and 21716666402.

It is not an unprimeable number, because it can be changed into a prime (21716666453) 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, 374425255 + ... + 374425312.

It is an arithmetic number, because the mean of its divisors is an integer number (5616379260).

Almost surely, 2^21716666443 is an apocalyptic number.

21716666443 is a deficient number, since it is larger than the sum of its proper divisors (748850597).

21716666443 is an equidigital number, since it uses as much as digits as its factorization.

21716666443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 748850596.

The product of its digits is 870912, while the sum is 46.

The spelling of 21716666443 in words is "twenty-one billion, seven hundred sixteen million, six hundred sixty-six thousand, four hundred forty-three".