21335357 has 4 divisors (see below), whose sum is σ = 22590396. Its totient is φ = 20080320.

The previous prime is 21335351. The next prime is 21335359. The reversal of 21335357 is 75353312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16556761 + 4778596 = 4069^2 + 2186^2 .

It is a cyclic number.

It is not a de Polignac number, because 21335357 - 2⁸ = 21335101 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 (21335351) 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 3 ways as a sum of consecutive naturals, for example, 627494 + ... + 627527.

It is an arithmetic number, because the mean of its divisors is an integer number (5647599).

Almost surely, 2^21335357 is an apocalyptic number.

It is an amenable number.

21335357 is a deficient number, since it is larger than the sum of its proper divisors (1255039).

21335357 is a wasteful number, since it uses less digits than its factorization.

21335357 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1255038.

The product of its digits is 9450, while the sum is 29.

The square root of 21335357 is about 4619.0212166648. The cubic root of 21335357 is about 277.3532790386.

Adding to 21335357 its reverse (75353312), we get a palindrome (96688669).

The spelling of 21335357 in words is "twenty-one million, three hundred thirty-five thousand, three hundred fifty-seven".