21038247 has 12 divisors (see below), whose sum is σ = 30577144. Its totient is φ = 13938480.

The previous prime is 21038219. The next prime is 21038249. The reversal of 21038247 is 74283012.

It is not a de Polignac number, because 21038247 - 2⁶ = 21038183 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21038247.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21038249) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5704 + ... + 8637.

Almost surely, 2^21038247 is an apocalyptic number.

21038247 is a deficient number, since it is larger than the sum of its proper divisors (9538897).

21038247 is a wasteful number, since it uses less digits than its factorization.

21038247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14510 (or 14507 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 21038247 is about 4586.7468864109. The cubic root of 21038247 is about 276.0598090297.

The spelling of 21038247 in words is "twenty-one million, thirty-eight thousand, two hundred forty-seven".