21643089 has 8 divisors (see below), whose sum is σ = 31077312. Its totient is φ = 13318800.

The previous prime is 21643087. The next prime is 21643099. The reversal of 21643089 is 98034612.

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

It is not a de Polignac number, because 21643089 - 2¹ = 21643087 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21643087) 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 7 ways as a sum of consecutive naturals, for example, 277437 + ... + 277514.

It is an arithmetic number, because the mean of its divisors is an integer number (3884664).

Almost surely, 2^21643089 is an apocalyptic number.

It is an amenable number.

21643089 is a deficient number, since it is larger than the sum of its proper divisors (9434223).

21643089 is a wasteful number, since it uses less digits than its factorization.

21643089 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 554967.

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 21643089 is about 4652.2133442051. The cubic root of 21643089 is about 278.6803935138.

It can be divided in two parts, 2164 and 3089, that added together give a triangular number (5253 = T₁₀₂).

The spelling of 21643089 in words is "twenty-one million, six hundred forty-three thousand, eighty-nine".