21880043 has 4 divisors (see below), whose sum is σ = 22292928. Its totient is φ = 21467160.

The previous prime is 21880009. The next prime is 21880057. The reversal of 21880043 is 34008812.

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 21880043 - 2¹⁰ = 21879019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21879994 and 21880021.

It is not an unprimeable number, because it can be changed into a prime (21880063) 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, 206363 + ... + 206468.

It is an arithmetic number, because the mean of its divisors is an integer number (5573232).

Almost surely, 2^21880043 is an apocalyptic number.

21880043 is a deficient number, since it is larger than the sum of its proper divisors (412885).

21880043 is an equidigital number, since it uses as much as digits as its factorization.

21880043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 412884.

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 21880043 is about 4677.6108217764. The cubic root of 21880043 is about 279.6937254817.

Adding to 21880043 its reverse (34008812), we get a palindrome (55888855).

The spelling of 21880043 in words is "twenty-one million, eight hundred eighty thousand, forty-three".