21330766 has 8 divisors (see below), whose sum is σ = 32159160. Its totient is φ = 10611048.

The previous prime is 21330761. The next prime is 21330781. The reversal of 21330766 is 66703312.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21330761) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26676 + ... + 27463.

It is an arithmetic number, because the mean of its divisors is an integer number (4019895).

Almost surely, 2^21330766 is an apocalyptic number.

21330766 is a deficient number, since it is larger than the sum of its proper divisors (10828394).

21330766 is a wasteful number, since it uses less digits than its factorization.

21330766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54338.

The product of its (nonzero) digits is 4536, while the sum is 28.

The square root of 21330766 is about 4618.5242231691. The cubic root of 21330766 is about 277.3333837345. Note that the first 4 decimals are identical.

The spelling of 21330766 in words is "twenty-one million, three hundred thirty thousand, seven hundred sixty-six".