21041145 has 24 divisors (see below), whose sum is σ = 36748296. Its totient is φ = 11136768.

The previous prime is 21041117. The next prime is 21041191. The reversal of 21041145 is 54114012.

21041145 is a `hidden beast` number, since 210 + 411 + 45 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 7469289 + 13571856 = 2733^2 + 3684^2 .

It is not a de Polignac number, because 21041145 - 2⁹ = 21040633 is a prime.

It is a super-2 number, since 2×21041145² = 885459565822050, which contains 22 as substring.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 4459 + ... + 7871.

It is an arithmetic number, because the mean of its divisors is an integer number (1531179).

Almost surely, 2^21041145 is an apocalyptic number.

It is an amenable number.

21041145 is a deficient number, since it is larger than the sum of its proper divisors (15707151).

21041145 is a wasteful number, since it uses less digits than its factorization.

21041145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3561 (or 3558 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 21041145 is about 4587.0627857050. The cubic root of 21041145 is about 276.0724841129.

Adding to 21041145 its reverse (54114012), we get a palindrome (75155157).

It can be divided in two parts, 2104 and 1145, that added together give a square (3249 = 57²).

The spelling of 21041145 in words is "twenty-one million, forty-one thousand, one hundred forty-five".