21458289 has 16 divisors (see below), whose sum is σ = 29805120. Its totient is φ = 13715520.

The previous prime is 21458279. The next prime is 21458303. The reversal of 21458289 is 98285412.

It is not a de Polignac number, because 21458289 - 2⁵ = 21458257 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21458279) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12874 + ... + 14444.

It is an arithmetic number, because the mean of its divisors is an integer number (1862820).

Almost surely, 2^21458289 is an apocalyptic number.

21458289 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

21458289 is a deficient number, since it is larger than the sum of its proper divisors (8346831).

21458289 is a wasteful number, since it uses less digits than its factorization.

21458289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1760.

The product of its digits is 46080, while the sum is 39.

The square root of 21458289 is about 4632.3092513346. The cubic root of 21458289 is about 277.8849523089.

The spelling of 21458289 in words is "twenty-one million, four hundred fifty-eight thousand, two hundred eighty-nine".