86405781 has 32 divisors (see below), whose sum is σ = 152091648. Its totient is φ = 42243840.

The previous prime is 86405777. The next prime is 86405801. The reversal of 86405781 is 18750468.

It is not a de Polignac number, because 86405781 - 2² = 86405777 is a prime.

It is a super-2 number, since 2×86405781² = 14931917980439922, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (86405701) 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 in 31 ways as a sum of consecutive naturals, for example, 7075 + ... + 14928.

It is an arithmetic number, because the mean of its divisors is an integer number (4752864).

Almost surely, 2^86405781 is an apocalyptic number.

It is an amenable number.

86405781 is a deficient number, since it is larger than the sum of its proper divisors (65685867).

86405781 is a wasteful number, since it uses less digits than its factorization.

86405781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22041.

The product of its (nonzero) digits is 53760, while the sum is 39.

The square root of 86405781 is about 9295.4709939841. The cubic root of 86405781 is about 442.0936395179.

The spelling of 86405781 in words is "eighty-six million, four hundred five thousand, seven hundred eighty-one".