21483581 has 4 divisors (see below), whose sum is σ = 24552672. Its totient is φ = 18414492.

The previous prime is 21483557. The next prime is 21483593. The reversal of 21483581 is 18538412.

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 21483581 - 2¹⁰ = 21482557 is a prime.

It is a super-2 number, since 2×21483581² = 923088505167122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21483481) 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, 1534535 + ... + 1534548.

It is an arithmetic number, because the mean of its divisors is an integer number (6138168).

Almost surely, 2^21483581 is an apocalyptic number.

It is an amenable number.

21483581 is a deficient number, since it is larger than the sum of its proper divisors (3069091).

21483581 is an equidigital number, since it uses as much as digits as its factorization.

21483581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3069090.

The product of its digits is 7680, while the sum is 32.

The square root of 21483581 is about 4635.0384032929. The cubic root of 21483581 is about 277.9940866192.

The spelling of 21483581 in words is "twenty-one million, four hundred eighty-three thousand, five hundred eighty-one".