81965887 has 2 divisors, whose sum is σ = 81965888. Its totient is φ = 81965886.

The previous prime is 81965881. The next prime is 81965893. The reversal of 81965887 is 78856918.

It is a balanced prime because it is at equal distance from previous prime (81965881) and next prime (81965893).

It is a cyclic number.

It is not a de Polignac number, because 81965887 - 2⁷ = 81965759 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81965881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40982943 + 40982944.

It is an arithmetic number, because the mean of its divisors is an integer number (40982944).

Almost surely, 2^81965887 is an apocalyptic number.

81965887 is a deficient number, since it is larger than the sum of its proper divisors (1).

81965887 is an equidigital number, since it uses as much as digits as its factorization.

81965887 is an evil number, because the sum of its binary digits is even.

The product of its digits is 967680, while the sum is 52.

The square root of 81965887 is about 9053.5013668746. The cubic root of 81965887 is about 434.3878949780.

The spelling of 81965887 in words is "eighty-one million, nine hundred sixty-five thousand, eight hundred eighty-seven".