9861591431 has 2 divisors, whose sum is σ = 9861591432. Its totient is φ = 9861591430.

The previous prime is 9861591323. The next prime is 9861591449. The reversal of 9861591431 is 1341951689.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 9861591431 - 2²⁶ = 9794482567 is a prime.

It is a super-2 number, since 2×9861591431² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9861591031) 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, 4930795715 + 4930795716.

It is an arithmetic number, because the mean of its divisors is an integer number (4930795716).

Almost surely, 2^9861591431 is an apocalyptic number.

9861591431 is a deficient number, since it is larger than the sum of its proper divisors (1).

9861591431 is an equidigital number, since it uses as much as digits as its factorization.

9861591431 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 233280, while the sum is 47.

The square root of 9861591431 is about 99305.5458219731. The cubic root of 9861591431 is about 2144.4487351997.

The spelling of 9861591431 in words is "nine billion, eight hundred sixty-one million, five hundred ninety-one thousand, four hundred thirty-one".