21461189 has 4 divisors (see below), whose sum is σ = 22201260. Its totient is φ = 20721120.

The previous prime is 21461179. The next prime is 21461201. The reversal of 21461189 is 98116412.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18130564 + 3330625 = 4258^2 + 1825^2 .

It is a cyclic number.

It is not a de Polignac number, because 21461189 - 2⁴ = 21461173 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21461179) 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 3 ways as a sum of consecutive naturals, for example, 369992 + ... + 370049.

It is an arithmetic number, because the mean of its divisors is an integer number (5550315).

Almost surely, 2^21461189 is an apocalyptic number.

21461189 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

21461189 is a deficient number, since it is larger than the sum of its proper divisors (740071).

21461189 is an equidigital number, since it uses as much as digits as its factorization.

21461189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 740070.

The product of its digits is 3456, while the sum is 32.

The square root of 21461189 is about 4632.6222595847. The cubic root of 21461189 is about 277.8974700833.

The spelling of 21461189 in words is "twenty-one million, four hundred sixty-one thousand, one hundred eighty-nine".