21713270 has 16 divisors (see below), whose sum is σ = 39255840. Its totient is φ = 8647104.

The previous prime is 21713261. The next prime is 21713273. The reversal of 21713270 is 7231712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21713273) 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 7 ways as a sum of consecutive naturals, for example, 2330 + ... + 6989.

It is an arithmetic number, because the mean of its divisors is an integer number (2453490).

Almost surely, 2^21713270 is an apocalyptic number.

21713270 is a deficient number, since it is larger than the sum of its proper divisors (17542570).

21713270 is a wasteful number, since it uses less digits than its factorization.

21713270 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9559.

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

The square root of 21713270 is about 4659.7499932936. The cubic root of 21713270 is about 278.9812896674.

Adding to 21713270 its reverse (7231712), we get a palindrome (28944982).

The spelling of 21713270 in words is "twenty-one million, seven hundred thirteen thousand, two hundred seventy".