21303844 has 6 divisors (see below), whose sum is σ = 37281734. Its totient is φ = 10651920.

The previous prime is 21303833. The next prime is 21303847. The reversal of 21303844 is 44830312.

It can be written as a sum of positive squares in only one way, i.e., 13249600 + 8054244 = 3640^2 + 2838^2 .

It is not an unprimeable number, because it can be changed into a prime (21303847) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2662977 + ... + 2662984.

Almost surely, 2^21303844 is an apocalyptic number.

It is an amenable number.

21303844 is a deficient number, since it is larger than the sum of its proper divisors (15977890).

21303844 is a wasteful number, since it uses less digits than its factorization.

21303844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5325965 (or 5325963 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 25.

The square root of 21303844 is about 4615.6087355841. The cubic root of 21303844 is about 277.2166585512.

The spelling of 21303844 in words is "twenty-one million, three hundred three thousand, eight hundred forty-four".