21143518 has 8 divisors (see below), whose sum is σ = 34598520. Its totient is φ = 9610680.

The previous prime is 21143497. The next prime is 21143533. The reversal of 21143518 is 81534112.

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

It is a junction number, because it is equal to n+sod(n) for n = 21143492 and 21143501.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 480513 + ... + 480556.

It is an arithmetic number, because the mean of its divisors is an integer number (4324815).

Almost surely, 2^21143518 is an apocalyptic number.

21143518 is a deficient number, since it is larger than the sum of its proper divisors (13455002).

21143518 is a wasteful number, since it uses less digits than its factorization.

21143518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 961082.

The product of its digits is 960, while the sum is 25.

The square root of 21143518 is about 4598.2081292608. The cubic root of 21143518 is about 276.5194917300.

The spelling of 21143518 in words is "twenty-one million, one hundred forty-three thousand, five hundred eighteen".