21285453 has 24 divisors (see below), whose sum is σ = 34756320. Its totient is φ = 11521440.

The previous prime is 21285421. The next prime is 21285463. The reversal of 21285453 is 35458212.

It is not a de Polignac number, because 21285453 - 2⁵ = 21285421 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21285453.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21285463) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1018 + ... + 6603.

It is an arithmetic number, because the mean of its divisors is an integer number (1448180).

Almost surely, 2^21285453 is an apocalyptic number.

It is an amenable number.

21285453 is a deficient number, since it is larger than the sum of its proper divisors (13470867).

21285453 is a wasteful number, since it uses less digits than its factorization.

21285453 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7657 (or 7650 counting only the distinct ones).

The product of its digits is 9600, while the sum is 30.

The square root of 21285453 is about 4613.6160438424. The cubic root of 21285453 is about 277.1368645112.

The spelling of 21285453 in words is "twenty-one million, two hundred eighty-five thousand, four hundred fifty-three".