21044249 has 4 divisors (see below), whose sum is σ = 22282164. Its totient is φ = 19806336.

The previous prime is 21044237. The next prime is 21044251. The reversal of 21044249 is 94244012.

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 7590025 + 13454224 = 2755^2 + 3668^2 .

It is a cyclic number.

It is not a de Polignac number, because 21044249 - 2⁸ = 21043993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21044269) 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, 618932 + ... + 618965.

It is an arithmetic number, because the mean of its divisors is an integer number (5570541).

Almost surely, 2^21044249 is an apocalyptic number.

It is an amenable number.

21044249 is a deficient number, since it is larger than the sum of its proper divisors (1237915).

21044249 is a wasteful number, since it uses less digits than its factorization.

21044249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1237914.

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 21044249 is about 4587.4011161005. The cubic root of 21044249 is about 276.0860588947.

The spelling of 21044249 in words is "twenty-one million, forty-four thousand, two hundred forty-nine".