21703172 has 12 divisors (see below), whose sum is σ = 38438736. Its totient is φ = 10720680.

The previous prime is 21703159. The next prime is 21703177. The reversal of 21703172 is 27130712.

It is a super-3 number, since 3×21703172³ (a number of 23 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21703177) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32354 + ... + 33017.

It is an arithmetic number, because the mean of its divisors is an integer number (3203228).

Almost surely, 2^21703172 is an apocalyptic number.

It is an amenable number.

21703172 is a deficient number, since it is larger than the sum of its proper divisors (16735564).

21703172 is a wasteful number, since it uses less digits than its factorization.

21703172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65458 (or 65456 counting only the distinct ones).

The product of its (nonzero) digits is 588, while the sum is 23.

The square root of 21703172 is about 4658.6663327609. Note that the first 3 decimals coincide. The cubic root of 21703172 is about 278.9380351677.

Adding to 21703172 its reverse (27130712), we get a palindrome (48833884).

The spelling of 21703172 in words is "twenty-one million, seven hundred three thousand, one hundred seventy-two".