21231331110247 has 2 divisors, whose sum is σ = 21231331110248. Its totient is φ = 21231331110246.

The previous prime is 21231331110239. The next prime is 21231331110293. The reversal of 21231331110247 is 74201113313212.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21231331110247 - 2³ = 21231331110239 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21231331110217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615665555123 + 10615665555124.

It is an arithmetic number, because the mean of its divisors is an integer number (10615665555124).

Almost surely, 2^{21231331110247} is an apocalyptic number.

21231331110247 is a deficient number, since it is larger than the sum of its proper divisors (1).

21231331110247 is an equidigital number, since it uses as much as digits as its factorization.

21231331110247 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6048, while the sum is 31.

Adding to 21231331110247 its reverse (74201113313212), we get a palindrome (95432444423459).

The spelling of 21231331110247 in words is "twenty-one trillion, two hundred thirty-one billion, three hundred thirty-one million, one hundred ten thousand, two hundred forty-seven".