21230481 has 4 divisors (see below), whose sum is σ = 28307312. Its totient is φ = 14153652.

The previous prime is 21230459. The next prime is 21230483. The reversal of 21230481 is 18403212.

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 not a de Polignac number, because 21230481 - 2²² = 17036177 is a prime.

It is a super-2 number, since 2×21230481² = 901466646982722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21230483) 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, 3538411 + ... + 3538416.

It is an arithmetic number, because the mean of its divisors is an integer number (7076828).

Almost surely, 2^21230481 is an apocalyptic number.

It is an amenable number.

21230481 is a deficient number, since it is larger than the sum of its proper divisors (7076831).

21230481 is an equidigital number, since it uses as much as digits as its factorization.

21230481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7076830.

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 21230481 is about 4607.6546094515. The cubic root of 21230481 is about 276.8980801214.

Adding to 21230481 its reverse (18403212), we get a palindrome (39633693).

The spelling of 21230481 in words is "twenty-one million, two hundred thirty thousand, four hundred eighty-one".