21453489 has 24 divisors (see below), whose sum is σ = 32947200. Its totient is φ = 13413600.

The previous prime is 21453469. The next prime is 21453493. The reversal of 21453489 is 98435412.

It is not a de Polignac number, because 21453489 - 2¹⁷ = 21322417 is a prime.

It is a zygodrome in base 3.

It is not an unprimeable number, because it can be changed into a prime (21453449) 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 23 ways as a sum of consecutive naturals, for example, 18064 + ... + 19214.

It is an arithmetic number, because the mean of its divisors is an integer number (1372800).

Almost surely, 2^21453489 is an apocalyptic number.

It is an amenable number.

21453489 is a deficient number, since it is larger than the sum of its proper divisors (11493711).

21453489 is a wasteful number, since it uses less digits than its factorization.

21453489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1285 (or 1282 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 21453489 is about 4631.7911222334. The cubic root of 21453489 is about 277.8642307556.

The spelling of 21453489 in words is "twenty-one million, four hundred fifty-three thousand, four hundred eighty-nine".