86544781 has 2 divisors, whose sum is σ = 86544782. Its totient is φ = 86544780.

The previous prime is 86544763. The next prime is 86544797. The reversal of 86544781 is 18744568.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 75429225 + 11115556 = 8685^2 + 3334^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-86544781 is a prime.

It is a super-2 number, since 2×86544781² = 14979998236675922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (86544701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43272390 + 43272391.

It is an arithmetic number, because the mean of its divisors is an integer number (43272391).

Almost surely, 2^86544781 is an apocalyptic number.

It is an amenable number.

86544781 is a deficient number, since it is larger than the sum of its proper divisors (1).

86544781 is an equidigital number, since it uses as much as digits as its factorization.

86544781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 215040, while the sum is 43.

The square root of 86544781 is about 9302.9447488416. The cubic root of 86544781 is about 442.3305761856.

The spelling of 86544781 in words is "eighty-six million, five hundred forty-four thousand, seven hundred eighty-one".