21453265 has 8 divisors (see below), whose sum is σ = 25908840. Its totient is φ = 17052672.

The previous prime is 21453253. The next prime is 21453283. The reversal of 21453265 is 56235412.

It can be written as a sum of positive squares in 4 ways, for example, as 877969 + 20575296 = 937^2 + 4536^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21453265 - 2¹¹ = 21451217 is a prime.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 12880 + ... + 14449.

It is an arithmetic number, because the mean of its divisors is an integer number (3238605).

Almost surely, 2^21453265 is an apocalyptic number.

It is an amenable number.

21453265 is a deficient number, since it is larger than the sum of its proper divisors (4455575).

21453265 is a wasteful number, since it uses less digits than its factorization.

21453265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27491.

The product of its digits is 7200, while the sum is 28.

The square root of 21453265 is about 4631.7669414598. The cubic root of 21453265 is about 277.8632636743.

Adding to 21453265 its reverse (56235412), we get a palindrome (77688677).

The spelling of 21453265 in words is "twenty-one million, four hundred fifty-three thousand, two hundred sixty-five".