86421605781 has 16 divisors (see below), whose sum is σ = 131701282304. Its totient is φ = 49379568624.

The previous prime is 86421605729. The next prime is 86421605797. The reversal of 86421605781 is 18750612468.

It is not a de Polignac number, because 86421605781 - 2¹⁰ = 86421604757 is a prime.

It is a super-3 number, since 3×86421605781³ (a number of 34 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 86421605781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (86421603781) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 86250 + ... + 424596.

It is an arithmetic number, because the mean of its divisors is an integer number (8231330144).

Almost surely, 2^86421605781 is an apocalyptic number.

It is an amenable number.

86421605781 is a deficient number, since it is larger than the sum of its proper divisors (45279676523).

86421605781 is a wasteful number, since it uses less digits than its factorization.

86421605781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 350520.

The product of its (nonzero) digits is 645120, while the sum is 48.

The spelling of 86421605781 in words is "eighty-six billion, four hundred twenty-one million, six hundred five thousand, seven hundred eighty-one".