21330787 has 8 divisors (see below), whose sum is σ = 22498560. Its totient is φ = 20167560.

The previous prime is 21330781. The next prime is 21330791. The reversal of 21330787 is 78703312.

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 21330787 - 2²³ = 12942179 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21330781) 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, 13362 + ... + 14872.

It is an arithmetic number, because the mean of its divisors is an integer number (2812320).

Almost surely, 2^21330787 is an apocalyptic number.

21330787 is a deficient number, since it is larger than the sum of its proper divisors (1167773).

21330787 is a wasteful number, since it uses less digits than its factorization.

21330787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2273.

The product of its (nonzero) digits is 7056, while the sum is 31.

The square root of 21330787 is about 4618.5264966221. The cubic root of 21330787 is about 277.3334747454. Note that the first 3 decimals are identical.

It can be divided in two parts, 213 and 30787, that multiplied together give a triangular number (6557631 = T₃₆₂₁).

The spelling of 21330787 in words is "twenty-one million, three hundred thirty thousand, seven hundred eighty-seven".