21021353 has 8 divisors (see below), whose sum is σ = 22170720. Its totient is φ = 19876320.

The previous prime is 21021349. The next prime is 21021359. The reversal of 21021353 is 35312012.

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 21021353 - 2² = 21021349 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21021359) 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, 15638 + ... + 16928.

It is an arithmetic number, because the mean of its divisors is an integer number (2771340).

Almost surely, 2^21021353 is an apocalyptic number.

It is an amenable number.

21021353 is a deficient number, since it is larger than the sum of its proper divisors (1149367).

21021353 is a wasteful number, since it uses less digits than its factorization.

21021353 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2167.

The product of its (nonzero) digits is 180, while the sum is 17.

The square root of 21021353 is about 4584.9049063203. The cubic root of 21021353 is about 275.9858959746.

Adding to 21021353 its reverse (35312012), we get a palindrome (56333365).

The spelling of 21021353 in words is "twenty-one million, twenty-one thousand, three hundred fifty-three".