21143524 has 6 divisors (see below), whose sum is σ = 37001174. Its totient is φ = 10571760.

The previous prime is 21143497. The next prime is 21143533. The reversal of 21143524 is 42534112.

It can be written as a sum of positive squares in only one way, i.e., 19272100 + 1871424 = 4390^2 + 1368^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21143495 and 21143504.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 2642937 + ... + 2642944.

Almost surely, 2^21143524 is an apocalyptic number.

It is an amenable number.

21143524 is a deficient number, since it is larger than the sum of its proper divisors (15857650).

21143524 is a wasteful number, since it uses less digits than its factorization.

21143524 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5285885 (or 5285883 counting only the distinct ones).

The product of its digits is 960, while the sum is 22.

The square root of 21143524 is about 4598.2087816888. The cubic root of 21143524 is about 276.5195178864.

Adding to 21143524 its reverse (42534112), we get a palindrome (63677636).

The spelling of 21143524 in words is "twenty-one million, one hundred forty-three thousand, five hundred twenty-four".