81868747 has 2 divisors, whose sum is σ = 81868748. Its totient is φ = 81868746.

The previous prime is 81868741. The next prime is 81868811. The reversal of 81868747 is 74786818.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81868747 - 2²³ = 73480139 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81868747.

It is not a weakly prime, because it can be changed into another prime (81868741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40934373 + 40934374.

It is an arithmetic number, because the mean of its divisors is an integer number (40934374).

Almost surely, 2^81868747 is an apocalyptic number.

81868747 is a deficient number, since it is larger than the sum of its proper divisors (1).

81868747 is an equidigital number, since it uses as much as digits as its factorization.

81868747 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 602112, while the sum is 49.

The square root of 81868747 is about 9048.1350012033. The cubic root of 81868747 is about 434.2162255107.

The spelling of 81868747 in words is "eighty-one million, eight hundred sixty-eight thousand, seven hundred forty-seven".