21003579 has 6 divisors (see below), whose sum is σ = 30338516. Its totient is φ = 14002380.

The previous prime is 21003557. The next prime is 21003589. The reversal of 21003579 is 97530012.

It is not a de Polignac number, because 21003579 - 2⁵ = 21003547 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21003509) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 1166857 + ... + 1166874.

Almost surely, 2^21003579 is an apocalyptic number.

21003579 is a deficient number, since it is larger than the sum of its proper divisors (9334937).

21003579 is a wasteful number, since it uses less digits than its factorization.

21003579 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2333737 (or 2333734 counting only the distinct ones).

The product of its (nonzero) digits is 1890, while the sum is 27.

The square root of 21003579 is about 4582.9661792337. The cubic root of 21003579 is about 275.9080900647.

The spelling of 21003579 in words is "twenty-one million, three thousand, five hundred seventy-nine".