21458789 has 8 divisors (see below), whose sum is σ = 24165120. Its totient is φ = 18878400.

The previous prime is 21458741. The next prime is 21458797. The reversal of 21458789 is 98785412.

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 21458789 - 2²⁰ = 20410213 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21458719) 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, 31124 + ... + 31805.

It is an arithmetic number, because the mean of its divisors is an integer number (3020640).

Almost surely, 2^21458789 is an apocalyptic number.

It is an amenable number.

21458789 is a deficient number, since it is larger than the sum of its proper divisors (2706331).

21458789 is a wasteful number, since it uses less digits than its factorization.

21458789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62971.

The product of its digits is 161280, while the sum is 44.

The square root of 21458789 is about 4632.3632197832. The cubic root of 21458789 is about 277.8871106263.

The spelling of 21458789 in words is "twenty-one million, four hundred fifty-eight thousand, seven hundred eighty-nine".