21224203015231 has 4 divisors (see below), whose sum is σ = 21224227054464. Its totient is φ = 21224178976000.

The previous prime is 21224203015207. The next prime is 21224203015241. The reversal of 21224203015231 is 13251030242212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21224203015231 - 2⁹ = 21224203014719 is a prime.

It is a super-2 number, since 2×21224203015231² (a number of 27 digits) contains 22 as substring.

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 21224203015231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21224203015241) 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 3 ways as a sum of consecutive naturals, for example, 10642690 + ... + 12478591.

It is an arithmetic number, because the mean of its divisors is an integer number (5306056763616).

Almost surely, 2^{21224203015231} is an apocalyptic number.

21224203015231 is a deficient number, since it is larger than the sum of its proper divisors (24039233).

21224203015231 is an equidigital number, since it uses as much as digits as its factorization.

21224203015231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24039232.

The product of its (nonzero) digits is 5760, while the sum is 28.

Adding to 21224203015231 its reverse (13251030242212), we get a palindrome (34475233257443).

The spelling of 21224203015231 in words is "twenty-one trillion, two hundred twenty-four billion, two hundred three million, fifteen thousand, two hundred thirty-one".