21184489 has 4 divisors (see below), whose sum is σ = 21351424. Its totient is φ = 21017556.

The previous prime is 21184469. The next prime is 21184511. The reversal of 21184489 is 98448112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21184489 - 2⁹ = 21183977 is a prime.

It is a super-2 number, since 2×21184489² = 897565148382242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21184469) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 83277 + ... + 83530.

It is an arithmetic number, because the mean of its divisors is an integer number (5337856).

Almost surely, 2^21184489 is an apocalyptic number.

It is an amenable number.

21184489 is a deficient number, since it is larger than the sum of its proper divisors (166935).

21184489 is a wasteful number, since it uses less digits than its factorization.

21184489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166934.

The product of its digits is 18432, while the sum is 37.

The square root of 21184489 is about 4602.6610781156. The cubic root of 21184489 is about 276.6979856805.

The spelling of 21184489 in words is "twenty-one million, one hundred eighty-four thousand, four hundred eighty-nine".