21054575 has 6 divisors (see below), whose sum is σ = 26107704. Its totient is φ = 16843640.

The previous prime is 21054569. The next prime is 21054601. The reversal of 21054575 is 57545012.

It is not a de Polignac number, because 21054575 - 2⁴ = 21054559 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 421067 + ... + 421116.

It is an arithmetic number, because the mean of its divisors is an integer number (4351284).

Almost surely, 2^21054575 is an apocalyptic number.

21054575 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21054575 is a deficient number, since it is larger than the sum of its proper divisors (5053129).

21054575 is an equidigital number, since it uses as much as digits as its factorization.

21054575 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 842193 (or 842188 counting only the distinct ones).

The product of its (nonzero) digits is 7000, while the sum is 29.

The square root of 21054575 is about 4588.5264519233. The cubic root of 21054575 is about 276.1312081812.

Adding to 21054575 its reverse (57545012), we get a palindrome (78599587).

The spelling of 21054575 in words is "twenty-one million, fifty-four thousand, five hundred seventy-five".