21053273 has 16 divisors (see below), whose sum is σ = 23052480. Its totient is φ = 19160064.

The previous prime is 21053269. The next prime is 21053281. The reversal of 21053273 is 37235012.

It is a cyclic number.

It is not a de Polignac number, because 21053273 - 2² = 21053269 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21053203) 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, 59465 + ... + 59817.

It is an arithmetic number, because the mean of its divisors is an integer number (1440780).

Almost surely, 2^21053273 is an apocalyptic number.

It is an amenable number.

21053273 is a deficient number, since it is larger than the sum of its proper divisors (1999207).

21053273 is a wasteful number, since it uses less digits than its factorization.

21053273 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 488.

The product of its (nonzero) digits is 1260, while the sum is 23.

The square root of 21053273 is about 4588.3845741176. The cubic root of 21053273 is about 276.1255161445.

Adding to 21053273 its reverse (37235012), we get a palindrome (58288285).

The spelling of 21053273 in words is "twenty-one million, fifty-three thousand, two hundred seventy-three".