21053533 has 8 divisors (see below), whose sum is σ = 22027968. Its totient is φ = 20084064.

The previous prime is 21053521. The next prime is 21053537. The reversal of 21053533 is 33535012.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21053533 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21053537) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9510 + ... + 11512.

It is an arithmetic number, because the mean of its divisors is an integer number (2753496).

Almost surely, 2^21053533 is an apocalyptic number.

21053533 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21053533 is a deficient number, since it is larger than the sum of its proper divisors (974435).

21053533 is a wasteful number, since it uses less digits than its factorization.

21053533 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2483.

The product of its (nonzero) digits is 1350, while the sum is 22.

The square root of 21053533 is about 4588.4129064416. The cubic root of 21053533 is about 276.1266528219.

Adding to 21053533 its reverse (33535012), we get a palindrome (54588545).

The spelling of 21053533 in words is "twenty-one million, fifty-three thousand, five hundred thirty-three".