21041505 has 16 divisors (see below), whose sum is σ = 37407360. Its totient is φ = 11222064.

The previous prime is 21041479. The next prime is 21041513. The reversal of 21041505 is 50514012.

It is not a de Polignac number, because 21041505 - 2⁶ = 21041441 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 77797 + ... + 78066.

It is an arithmetic number, because the mean of its divisors is an integer number (2337960).

Almost surely, 2^21041505 is an apocalyptic number.

It is an amenable number.

21041505 is a deficient number, since it is larger than the sum of its proper divisors (16365855).

21041505 is a wasteful number, since it uses less digits than its factorization.

21041505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155877 (or 155871 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

The square root of 21041505 is about 4587.1020263343. The cubic root of 21041505 is about 276.0740585761.

Adding to 21041505 its reverse (50514012), we get a palindrome (71555517).

The spelling of 21041505 in words is "twenty-one million, forty-one thousand, five hundred five".