21064717 has 8 divisors (see below), whose sum is σ = 23023872. Its totient is φ = 19185600.

The previous prime is 21064679. The next prime is 21064723. The reversal of 21064717 is 71746012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21064717 - 2²³ = 12676109 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21064117) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19459 + ... + 20512.

It is an arithmetic number, because the mean of its divisors is an integer number (2877984).

Almost surely, 2^21064717 is an apocalyptic number.

It is an amenable number.

21064717 is a deficient number, since it is larger than the sum of its proper divisors (1959155).

21064717 is a wasteful number, since it uses less digits than its factorization.

21064717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40019.

The product of its (nonzero) digits is 2352, while the sum is 28.

The square root of 21064717 is about 4589.6314666866. The cubic root of 21064717 is about 276.1755385807.

The spelling of 21064717 in words is "twenty-one million, sixty-four thousand, seven hundred seventeen".