21041355 has 16 divisors (see below), whose sum is σ = 33995520. Its totient is φ = 11112288.

The previous prime is 21041353. The next prime is 21041357. The reversal of 21041355 is 55314012.

21041355 = 400² + 401² + ... + 502².

It is an interprime number because it is at equal distance from previous prime (21041353) and next prime (21041357).

It is not a de Polignac number, because 21041355 - 2¹ = 21041353 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21041353) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5265 + ... + 8354.

It is an arithmetic number, because the mean of its divisors is an integer number (2124720).

Almost surely, 2^21041355 is an apocalyptic number.

21041355 is a deficient number, since it is larger than the sum of its proper divisors (12954165).

21041355 is a wasteful number, since it uses less digits than its factorization.

21041355 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13730.

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 21041355 is about 4587.0856761129. The cubic root of 21041355 is about 276.0734025520.

Adding to 21041355 its reverse (55314012), we get a palindrome (76355367).

The spelling of 21041355 in words is "twenty-one million, forty-one thousand, three hundred fifty-five".