21330055 has 8 divisors (see below), whose sum is σ = 25710192. Its totient is φ = 16987968.

The previous prime is 21330047. The next prime is 21330059. The reversal of 21330055 is 55003312.

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 21330055 - 2³ = 21330047 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21330059) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8262 + ... + 10531.

It is an arithmetic number, because the mean of its divisors is an integer number (3213774).

Almost surely, 2^21330055 is an apocalyptic number.

21330055 is a deficient number, since it is larger than the sum of its proper divisors (4380137).

21330055 is a wasteful number, since it uses less digits than its factorization.

21330055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19025.

The product of its (nonzero) digits is 450, while the sum is 19.

The square root of 21330055 is about 4618.4472498882. The cubic root of 21330055 is about 277.3303023289.

Adding to 21330055 its reverse (55003312), we get a palindrome (76333367).

The spelling of 21330055 in words is "twenty-one million, three hundred thirty thousand, fifty-five".