21500235230247 has 12 divisors (see below), whose sum is σ = 31565008371624. Its totient is φ = 14098514904720.

The previous prime is 21500235230219. The next prime is 21500235230273. The reversal of 21500235230247 is 74203253200512.

21500235230247 is a `hidden beast` number, since 2 + 150 + 0 + 2 + 35 + 230 + 247 = 666.

It is not a de Polignac number, because 21500235230247 - 2³¹ = 21498087746599 is a prime.

It is a super-2 number, since 2×21500235230247² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21500235230147) 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 11 ways as a sum of consecutive naturals, for example, 19581270153 + ... + 19581271250.

It is an arithmetic number, because the mean of its divisors is an integer number (2630417364302).

Almost surely, 2^{21500235230247} is an apocalyptic number.

21500235230247 is a deficient number, since it is larger than the sum of its proper divisors (10064773141377).

21500235230247 is a wasteful number, since it uses less digits than its factorization.

21500235230247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39162541470 (or 39162541467 counting only the distinct ones).

The product of its (nonzero) digits is 100800, while the sum is 36.

Adding to 21500235230247 its reverse (74203253200512), we get a palindrome (95703488430759).

The spelling of 21500235230247 in words is "twenty-one trillion, five hundred billion, two hundred thirty-five million, two hundred thirty thousand, two hundred forty-seven".