21043355 has 8 divisors (see below), whose sum is σ = 26581200. Its totient is φ = 15948576.

The previous prime is 21043339. The next prime is 21043381. The reversal of 21043355 is 55334012.

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

It is a cyclic number.

It is not a de Polignac number, because 21043355 - 2⁴ = 21043339 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21043355.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 110660 + ... + 110849.

It is an arithmetic number, because the mean of its divisors is an integer number (3322650).

Almost surely, 2^21043355 is an apocalyptic number.

21043355 is a deficient number, since it is larger than the sum of its proper divisors (5537845).

21043355 is a wasteful number, since it uses less digits than its factorization.

21043355 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221533.

The product of its (nonzero) digits is 1800, while the sum is 23.

The square root of 21043355 is about 4587.3036742732. The cubic root of 21043355 is about 276.0821492845.

Adding to 21043355 its reverse (55334012), we get a palindrome (76377367).

The spelling of 21043355 in words is "twenty-one million, forty-three thousand, three hundred fifty-five".