21053285 has 16 divisors (see below), whose sum is σ = 27682560. Its totient is φ = 15243840.

The previous prime is 21053281. The next prime is 21053287. The reversal of 21053285 is 58235012.

It is not a de Polignac number, because 21053285 - 2² = 21053281 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21053281) 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 15 ways as a sum of consecutive naturals, for example, 14084 + ... + 15506.

It is an arithmetic number, because the mean of its divisors is an integer number (1730160).

Almost surely, 2^21053285 is an apocalyptic number.

It is an amenable number.

21053285 is a deficient number, since it is larger than the sum of its proper divisors (6629275).

21053285 is a wasteful number, since it uses less digits than its factorization.

21053285 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1708.

The product of its (nonzero) digits is 2400, while the sum is 26.

The square root of 21053285 is about 4588.3858817671. The cubic root of 21053285 is about 276.1255686067.

Adding to 21053285 its reverse (58235012), we get a palindrome (79288297).

The spelling of 21053285 in words is "twenty-one million, fifty-three thousand, two hundred eighty-five".