21789067 has 4 divisors (see below), whose sum is σ = 22935880. Its totient is φ = 20642256.

The previous prime is 21789043. The next prime is 21789071. The reversal of 21789067 is 76098712.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21789067 - 2²³ = 13400459 is a prime.

It is a Duffinian number.

It is a zygodrome in base 3.

It is not an unprimeable number, because it can be changed into a prime (21789007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 573378 + ... + 573415.

It is an arithmetic number, because the mean of its divisors is an integer number (5733970).

Almost surely, 2^21789067 is an apocalyptic number.

21789067 is a deficient number, since it is larger than the sum of its proper divisors (1146813).

21789067 is a wasteful number, since it uses less digits than its factorization.

21789067 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1146812.

The product of its (nonzero) digits is 42336, while the sum is 40.

The square root of 21789067 is about 4667.8760694774. The cubic root of 21789067 is about 279.3055366508.

The spelling of 21789067 in words is "twenty-one million, seven hundred eighty-nine thousand, sixty-seven".