21855355 has 8 divisors (see below), whose sum is σ = 26337600. Its totient is φ = 17410176.

The previous prime is 21855349. The next prime is 21855367. The reversal of 21855355 is 55355812.

21855355 is nontrivially palindromic in base 12.

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 21855355 - 2⁷ = 21855227 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21855355.

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, 7950 + ... + 10339.

It is an arithmetic number, because the mean of its divisors is an integer number (3292200).

Almost surely, 2^21855355 is an apocalyptic number.

21855355 is a deficient number, since it is larger than the sum of its proper divisors (4482245).

21855355 is a wasteful number, since it uses less digits than its factorization.

21855355 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18533.

The product of its digits is 30000, while the sum is 34.

The square root of 21855355 is about 4674.9711229055. The cubic root of 21855355 is about 279.5884898963.

The spelling of 21855355 in words is "twenty-one million, eight hundred fifty-five thousand, three hundred fifty-five".