21704767 has 12 divisors (see below), whose sum is σ = 26352880. Its totient is φ = 17508096.

The previous prime is 21704737. The next prime is 21704791. The reversal of 21704767 is 76740712.

It is not a de Polignac number, because 21704767 - 2¹¹ = 21702719 is a prime.

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21704737) 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 11 ways as a sum of consecutive naturals, for example, 3342 + ... + 7387.

Almost surely, 2^21704767 is an apocalyptic number.

21704767 is a deficient number, since it is larger than the sum of its proper divisors (4648113).

21704767 is a wasteful number, since it uses less digits than its factorization.

21704767 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10770 (or 10753 counting only the distinct ones).

The product of its (nonzero) digits is 16464, while the sum is 34.

The square root of 21704767 is about 4658.8375159475. The cubic root of 21704767 is about 278.9448681975.

The spelling of 21704767 in words is "twenty-one million, seven hundred four thousand, seven hundred sixty-seven".