21166541043 has 4 divisors (see below), whose sum is σ = 28222054728. Its totient is φ = 14111027360.

The previous prime is 21166541017. The next prime is 21166541051. The reversal of 21166541043 is 34014566112.

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 21166541043 - 2¹⁶ = 21166475507 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21166540995 and 21166541013.

It is not an unprimeable number, because it can be changed into a prime (21166541003) 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, 3527756838 + ... + 3527756843.

It is an arithmetic number, because the mean of its divisors is an integer number (7055513682).

Almost surely, 2^21166541043 is an apocalyptic number.

21166541043 is a deficient number, since it is larger than the sum of its proper divisors (7055513685).

21166541043 is an equidigital number, since it uses as much as digits as its factorization.

21166541043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7055513684.

The product of its (nonzero) digits is 17280, while the sum is 33.

The spelling of 21166541043 in words is "twenty-one billion, one hundred sixty-six million, five hundred forty-one thousand, forty-three".