21053255 has 8 divisors (see below), whose sum is σ = 25342224. Its totient is φ = 16790400.

The previous prime is 21053203. The next prime is 21053267. The reversal of 21053255 is 55235012.

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

It is a de Polignac number, because none of the positive numbers 2^k-21053255 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21053255.

It is a congruent number.

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, 4706 + ... + 8015.

It is an arithmetic number, because the mean of its divisors is an integer number (3167778).

Almost surely, 2^21053255 is an apocalyptic number.

21053255 is a deficient number, since it is larger than the sum of its proper divisors (4288969).

21053255 is a wasteful number, since it uses less digits than its factorization.

21053255 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13057.

The product of its (nonzero) digits is 1500, while the sum is 23.

The square root of 21053255 is about 4588.3826126425. The cubic root of 21053255 is about 276.1254374511.

Adding to 21053255 its reverse (55235012), we get a palindrome (76288267).

The spelling of 21053255 in words is "twenty-one million, fifty-three thousand, two hundred fifty-five".