21056753 has 8 divisors (see below), whose sum is σ = 22032000. Its totient is φ = 20086528.

The previous prime is 21056743. The next prime is 21056801. The reversal of 21056753 is 35765012.

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 21056753 - 2⁶ = 21056689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21056723) 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 7 ways as a sum of consecutive naturals, for example, 9308 + ... + 11346.

It is an arithmetic number, because the mean of its divisors is an integer number (2754000).

Almost surely, 2^21056753 is an apocalyptic number.

21056753 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21056753 is a deficient number, since it is larger than the sum of its proper divisors (975247).

21056753 is a wasteful number, since it uses less digits than its factorization.

21056753 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2511.

The product of its (nonzero) digits is 6300, while the sum is 29.

The square root of 21056753 is about 4588.7637768793. The cubic root of 21056753 is about 276.1407293587.

The spelling of 21056753 in words is "twenty-one million, fifty-six thousand, seven hundred fifty-three".