21131202247 has 2 divisors, whose sum is σ = 21131202248. Its totient is φ = 21131202246.

The previous prime is 21131202227. The next prime is 21131202251. The reversal of 21131202247 is 74220213112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21131202247 - 2¹¹ = 21131200199 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21131202227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10565601123 + 10565601124.

It is an arithmetic number, because the mean of its divisors is an integer number (10565601124).

Almost surely, 2^21131202247 is an apocalyptic number.

21131202247 is a deficient number, since it is larger than the sum of its proper divisors (1).

21131202247 is an equidigital number, since it uses as much as digits as its factorization.

21131202247 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1344, while the sum is 25.

Adding to 21131202247 its reverse (74220213112), we get a palindrome (95351415359).

The spelling of 21131202247 in words is "twenty-one billion, one hundred thirty-one million, two hundred two thousand, two hundred forty-seven".