21221170 has 16 divisors (see below), whose sum is σ = 38257920. Its totient is φ = 8475184.

The previous prime is 21221153. The next prime is 21221171. The reversal of 21221170 is 7112212.

It is not an unprimeable number, because it can be changed into a prime (21221171) 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, 7401 + ... + 9859.

It is an arithmetic number, because the mean of its divisors is an integer number (2391120).

Almost surely, 2^21221170 is an apocalyptic number.

21221170 is a deficient number, since it is larger than the sum of its proper divisors (17036750).

21221170 is a wasteful number, since it uses less digits than its factorization.

21221170 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3329.

The product of its (nonzero) digits is 56, while the sum is 16.

The square root of 21221170 is about 4606.6441147543. The cubic root of 21221170 is about 276.8575946983.

Adding to 21221170 its reverse (7112212), we get a palindrome (28333382).

The spelling of 21221170 in words is "twenty-one million, two hundred twenty-one thousand, one hundred seventy".