21415705717 has 16 divisors (see below), whose sum is σ = 24897571200. Its totient is φ = 18039651840.

The previous prime is 21415705643. The next prime is 21415705739. The reversal of 21415705717 is 71750751412.

It is not a de Polignac number, because 21415705717 - 2¹¹ = 21415703669 is a prime.

It is a super-3 number, since 3×21415705717³ (a number of 32 digits) contains 333 as substring.

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 21415705717.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21415705747) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1878009 + ... + 1889377.

It is an arithmetic number, because the mean of its divisors is an integer number (1556098200).

Almost surely, 2^21415705717 is an apocalyptic number.

It is an amenable number.

21415705717 is a deficient number, since it is larger than the sum of its proper divisors (3481865483).

21415705717 is a wasteful number, since it uses less digits than its factorization.

21415705717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15996.

The product of its (nonzero) digits is 68600, while the sum is 40.

The spelling of 21415705717 in words is "twenty-one billion, four hundred fifteen million, seven hundred five thousand, seven hundred seventeen".