21003359 has 4 divisors (see below), whose sum is σ = 22619016. Its totient is φ = 19387704.

The previous prime is 21003349. The next prime is 21003371. The reversal of 21003359 is 95330012.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21003359 - 2⁴ = 21003343 is a prime.

It is a super-2 number, since 2×21003359² = 882282178565762, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

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 (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 807809 + ... + 807834.

It is an arithmetic number, because the mean of its divisors is an integer number (5654754).

Almost surely, 2^21003359 is an apocalyptic number.

21003359 is a deficient number, since it is larger than the sum of its proper divisors (1615657).

21003359 is a wasteful number, since it uses less digits than its factorization.

21003359 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1615656.

The product of its (nonzero) digits is 810, while the sum is 23.

The square root of 21003359 is about 4582.9421772481. The cubic root of 21003359 is about 275.9071267369.

The spelling of 21003359 in words is "twenty-one million, three thousand, three hundred fifty-nine".