21315041505 has 24 divisors (see below), whose sum is σ = 38552424768. Its totient is φ = 10873759776.

The previous prime is 21315041431. The next prime is 21315041509. The reversal of 21315041505 is 50514051312.

21315041505 is a `hidden beast` number, since 2 + 1 + 3 + 1 + 504 + 150 + 5 = 666.

It is not a de Polignac number, because 21315041505 - 2⁸ = 21315041249 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21315041509) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10296087 + ... + 10298156.

It is an arithmetic number, because the mean of its divisors is an integer number (1606351032).

Almost surely, 2^21315041505 is an apocalyptic number.

It is an amenable number.

21315041505 is a deficient number, since it is larger than the sum of its proper divisors (17237383263).

21315041505 is a wasteful number, since it uses less digits than its factorization.

21315041505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20594277 (or 20594274 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 27.

Adding to 21315041505 its reverse (50514051312), we get a palindrome (71829092817).

The spelling of 21315041505 in words is "twenty-one billion, three hundred fifteen million, forty-one thousand, five hundred five".