21515050243201 has 4 divisors (see below), whose sum is σ = 21627694485504. Its totient is φ = 21402406000900.

The previous prime is 21515050243199. The next prime is 21515050243223. The reversal of 21515050243201 is 10234205051512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21515050243201 - 2¹ = 21515050243199 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21515050243301) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 56322120865 + ... + 56322121246.

It is an arithmetic number, because the mean of its divisors is an integer number (5406923621376).

Almost surely, 2^{21515050243201} is an apocalyptic number.

It is an amenable number.

21515050243201 is a deficient number, since it is larger than the sum of its proper divisors (112644242303).

21515050243201 is a wasteful number, since it uses less digits than its factorization.

21515050243201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112644242302.

The product of its (nonzero) digits is 12000, while the sum is 31.

Adding to 21515050243201 its reverse (10234205051512), we get a palindrome (31749255294713).

The spelling of 21515050243201 in words is "twenty-one trillion, five hundred fifteen billion, fifty million, two hundred forty-three thousand, two hundred one".