21145443 has 8 divisors (see below), whose sum is σ = 30757056. Its totient is φ = 12815400.

The previous prime is 21145429. The next prime is 21145451. The reversal of 21145443 is 34454112.

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

It is not a de Polignac number, because 21145443 - 2⁴ = 21145427 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21145403) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 320353 + ... + 320418.

It is an arithmetic number, because the mean of its divisors is an integer number (3844632).

Almost surely, 2^21145443 is an apocalyptic number.

21145443 is a deficient number, since it is larger than the sum of its proper divisors (9611613).

21145443 is a wasteful number, since it uses less digits than its factorization.

21145443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 640785.

The product of its digits is 1920, while the sum is 24.

The square root of 21145443 is about 4598.4174451652. The cubic root of 21145443 is about 276.5278833305.

Adding to 21145443 its reverse (34454112), we get a palindrome (55599555).

It can be divided in two parts, 2114 and 5443, that added together give a palindrome (7557).

The spelling of 21145443 in words is "twenty-one million, one hundred forty-five thousand, four hundred forty-three".