21453513 has 8 divisors (see below), whose sum is σ = 28667808. Its totient is φ = 14270784.

The previous prime is 21453493. The next prime is 21453529. The reversal of 21453513 is 31535412.

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

It is not a de Polignac number, because 21453513 - 2⁶ = 21453449 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21453563) 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 7 ways as a sum of consecutive naturals, for example, 6256 + ... + 9057.

It is an arithmetic number, because the mean of its divisors is an integer number (3583476).

Almost surely, 2^21453513 is an apocalyptic number.

It is an amenable number.

21453513 is a deficient number, since it is larger than the sum of its proper divisors (7214295).

21453513 is a wasteful number, since it uses less digits than its factorization.

21453513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15783.

The product of its digits is 1800, while the sum is 24.

The square root of 21453513 is about 4631.7937130231. The cubic root of 21453513 is about 277.8643343710.

Adding to 21453513 its reverse (31535412), we get a palindrome (52988925).

The spelling of 21453513 in words is "twenty-one million, four hundred fifty-three thousand, five hundred thirteen".