21053170 has 8 divisors (see below), whose sum is σ = 37895724. Its totient is φ = 8421264.

The previous prime is 21053129. The next prime is 21053173. The reversal of 21053170 is 7135012.

It can be written as a sum of positive squares in 2 ways, for example, as 20277009 + 776161 = 4503^2 + 881^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (21053173) 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 3 ways as a sum of consecutive naturals, for example, 1052649 + ... + 1052668.

Almost surely, 2^21053170 is an apocalyptic number.

21053170 is a deficient number, since it is larger than the sum of its proper divisors (16842554).

21053170 is a wasteful number, since it uses less digits than its factorization.

21053170 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2105324.

The product of its (nonzero) digits is 210, while the sum is 19.

The square root of 21053170 is about 4588.3733501100. The cubic root of 21053170 is about 276.1250658427.

Adding to 21053170 its reverse (7135012), we get a palindrome (28188182).

The spelling of 21053170 in words is "twenty-one million, fifty-three thousand, one hundred seventy".