21459189 has 8 divisors (see below), whose sum is σ = 30118240. Its totient is φ = 13553136.

The previous prime is 21459187. The next prime is 21459197. The reversal of 21459189 is 98195412.

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

It is not a de Polignac number, because 21459189 - 2¹ = 21459187 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 (21459181) 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, 188182 + ... + 188295.

It is an arithmetic number, because the mean of its divisors is an integer number (3764780).

Almost surely, 2^21459189 is an apocalyptic number.

It is an amenable number.

21459189 is a deficient number, since it is larger than the sum of its proper divisors (8659051).

21459189 is a wasteful number, since it uses less digits than its factorization.

21459189 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 376499.

The product of its digits is 25920, while the sum is 39.

The square root of 21459189 is about 4632.4063940894. The cubic root of 21459189 is about 277.8888372561. Note that the first 4 decimals are identical.

The spelling of 21459189 in words is "twenty-one million, four hundred fifty-nine thousand, one hundred eighty-nine".