21003448 has 16 divisors (see below), whose sum is σ = 39432960. Its totient is φ = 10488000.

The previous prime is 21003431. The next prime is 21003473. The reversal of 21003448 is 84430012.

It is a super-2 number, since 2×21003448² = 882289655777408, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8068 + ... + 10348.

It is an arithmetic number, because the mean of its divisors is an integer number (2464560).

Almost surely, 2^21003448 is an apocalyptic number.

It is an amenable number.

21003448 is a deficient number, since it is larger than the sum of its proper divisors (18429512).

21003448 is a wasteful number, since it uses less digits than its factorization.

21003448 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3438 (or 3434 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 21003448 is about 4582.9518871574. The cubic root of 21003448 is about 275.9075164476.

The spelling of 21003448 in words is "twenty-one million, three thousand, four hundred forty-eight".