21175144 has 8 divisors (see below), whose sum is σ = 39703410. Its totient is φ = 10587568.

The previous prime is 21175129. The next prime is 21175151. The reversal of 21175144 is 44157112.

It can be written as a sum of positive squares in only one way, i.e., 14152644 + 7022500 = 3762^2 + 2650^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 1323439 + ... + 1323454.

Almost surely, 2^21175144 is an apocalyptic number.

It is an amenable number.

21175144 is a deficient number, since it is larger than the sum of its proper divisors (18528266).

21175144 is a wasteful number, since it uses less digits than its factorization.

21175144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2646899 (or 2646895 counting only the distinct ones).

The product of its digits is 1120, while the sum is 25.

The square root of 21175144 is about 4601.6457925399. The cubic root of 21175144 is about 276.6572935971.

The spelling of 21175144 in words is "twenty-one million, one hundred seventy-five thousand, one hundred forty-four".