21710117 has 16 divisors (see below), whose sum is σ = 25694592. Its totient is φ = 18083520.

The previous prime is 21710113. The next prime is 21710123. The reversal of 21710117 is 71101712.

It is not a de Polignac number, because 21710117 - 2² = 21710113 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21710111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21968 + ... + 22934.

It is an arithmetic number, because the mean of its divisors is an integer number (1605912).

Almost surely, 2^21710117 is an apocalyptic number.

It is an amenable number.

21710117 is a deficient number, since it is larger than the sum of its proper divisors (3984475).

21710117 is a wasteful number, since it uses less digits than its factorization.

21710117 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1148.

The product of its (nonzero) digits is 98, while the sum is 20.

The square root of 21710117 is about 4659.4116581388. The cubic root of 21710117 is about 278.9677853205.

Adding to 21710117 its reverse (71101712), we get a palindrome (92811829).

The spelling of 21710117 in words is "twenty-one million, seven hundred ten thousand, one hundred seventeen".