21544130 has 8 divisors (see below), whose sum is σ = 38779452. Its totient is φ = 8617648.

The previous prime is 21544109. The next prime is 21544139. The reversal of 21544130 is 3144512.

It can be written as a sum of positive squares in 2 ways, for example, as 21446161 + 97969 = 4631^2 + 313^2 .

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21544139) by changing a digit.

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 in 3 ways as a sum of consecutive naturals, for example, 1077197 + ... + 1077216.

Almost surely, 2^21544130 is an apocalyptic number.

21544130 is a deficient number, since it is larger than the sum of its proper divisors (17235322).

21544130 is a wasteful number, since it uses less digits than its factorization.

21544130 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2154420.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 21544130 is about 4641.5654686754. The cubic root of 21544130 is about 278.2550064258.

Adding to 21544130 its reverse (3144512), we get a palindrome (24688642).

The spelling of 21544130 in words is "twenty-one million, five hundred forty-four thousand, one hundred thirty".