9781012231 has 2 divisors, whose sum is σ = 9781012232. Its totient is φ = 9781012230.

The previous prime is 9781012229. The next prime is 9781012247. The reversal of 9781012231 is 1322101879.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 9781012231 - 2¹ = 9781012229 is a prime.

It is a super-2 number, since 2×9781012231² (a number of 21 digits) contains 22 as substring.

Together with 9781012229, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9781012331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4890506115 + 4890506116.

It is an arithmetic number, because the mean of its divisors is an integer number (4890506116).

Almost surely, 2^9781012231 is an apocalyptic number.

9781012231 is a deficient number, since it is larger than the sum of its proper divisors (1).

9781012231 is an equidigital number, since it uses as much as digits as its factorization.

9781012231 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6048, while the sum is 34.

The square root of 9781012231 is about 98899.0001516699. Note that the first 3 decimals coincide. The cubic root of 9781012231 is about 2138.5919808153.

The spelling of 9781012231 in words is "nine billion, seven hundred eighty-one million, twelve thousand, two hundred thirty-one".