21003369 has 4 divisors (see below), whose sum is σ = 28004496. Its totient is φ = 14002244.

The previous prime is 21003349. The next prime is 21003371. The reversal of 21003369 is 96330012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21003369 - 2⁹ = 21002857 is a prime.

It is a super-2 number, since 2×21003369² = 882283018700322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21003329) by changing a digit.

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, 3500559 + ... + 3500564.

It is an arithmetic number, because the mean of its divisors is an integer number (7001124).

Almost surely, 2^21003369 is an apocalyptic number.

It is an amenable number.

21003369 is a deficient number, since it is larger than the sum of its proper divisors (7001127).

21003369 is an equidigital number, since it uses as much as digits as its factorization.

21003369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7001126.

The product of its (nonzero) digits is 972, while the sum is 24.

The square root of 21003369 is about 4582.9432682502. The cubic root of 21003369 is about 275.9071705247.

The spelling of 21003369 in words is "twenty-one million, three thousand, three hundred sixty-nine".