21034445 has 4 divisors (see below), whose sum is σ = 25241340. Its totient is φ = 16827552.

The previous prime is 21034421. The next prime is 21034471. The reversal of 21034445 is 54443012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9872164 + 11162281 = 3142^2 + 3341^2 .

It is a cyclic number.

It is not a de Polignac number, because 21034445 - 2²⁰ = 19985869 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21034445.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2103440 + ... + 2103449.

It is an arithmetic number, because the mean of its divisors is an integer number (6310335).

Almost surely, 2^21034445 is an apocalyptic number.

It is an amenable number.

21034445 is a deficient number, since it is larger than the sum of its proper divisors (4206895).

21034445 is an equidigital number, since it uses as much as digits as its factorization.

21034445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4206894.

The product of its (nonzero) digits is 1920, while the sum is 23.

The square root of 21034445 is about 4586.3324127237. The cubic root of 21034445 is about 276.0431783249.

Adding to 21034445 its reverse (54443012), we get a palindrome (75477457).

The spelling of 21034445 in words is "twenty-one million, thirty-four thousand, four hundred forty-five".