21000241015 has 16 divisors (see below), whose sum is σ = 28735172928. Its totient is φ = 14595641856.

The previous prime is 21000241013. The next prime is 21000241081. The reversal of 21000241015 is 51014200012.

It is not a de Polignac number, because 21000241015 - 2¹ = 21000241013 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21000241015.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000241013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9501267 + ... + 9503476.

It is an arithmetic number, because the mean of its divisors is an integer number (1795948308).

Almost surely, 2^21000241015 is an apocalyptic number.

21000241015 is a deficient number, since it is larger than the sum of its proper divisors (7734931913).

21000241015 is a wasteful number, since it uses less digits than its factorization.

21000241015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19004778.

The product of its (nonzero) digits is 80, while the sum is 16.

Adding to 21000241015 its reverse (51014200012), we get a palindrome (72014441027).

The spelling of 21000241015 in words is "twenty-one billion, two hundred forty-one thousand, fifteen".