81885707 has 2 divisors, whose sum is σ = 81885708. Its totient is φ = 81885706.

The previous prime is 81885691. The next prime is 81885731. The reversal of 81885707 is 70758818.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81885707 - 2⁴ = 81885691 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81885737) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40942853 + 40942854.

It is an arithmetic number, because the mean of its divisors is an integer number (40942854).

Almost surely, 2^81885707 is an apocalyptic number.

81885707 is a deficient number, since it is larger than the sum of its proper divisors (1).

81885707 is an equidigital number, since it uses as much as digits as its factorization.

81885707 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 125440, while the sum is 44.

The square root of 81885707 is about 9049.0721623822. The cubic root of 81885707 is about 434.2462076426.

The spelling of 81885707 in words is "eighty-one million, eight hundred eighty-five thousand, seven hundred seven".