86123781 has 24 divisors (see below), whose sum is σ = 128583936. Its totient is φ = 55517280.

The previous prime is 86123773. The next prime is 86123783. The reversal of 86123781 is 18732168.

86123781 is a `hidden beast` number, since 8 + 612 + 37 + 8 + 1 = 666.

It is not a de Polignac number, because 86123781 - 2³ = 86123773 is a prime.

It is a super-2 number, since 2×86123781² = 14834611307471922, which contains 22 as substring.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (86123783) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 32596 + ... + 35138.

It is an arithmetic number, because the mean of its divisors is an integer number (5357664).

Almost surely, 2^86123781 is an apocalyptic number.

It is an amenable number.

86123781 is a deficient number, since it is larger than the sum of its proper divisors (42460155).

86123781 is a wasteful number, since it uses less digits than its factorization.

86123781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2673 (or 2670 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 86123781 is about 9280.2899200402. The cubic root of 86123781 is about 441.6121660214.

It can be divided in two parts, 861 and 23781, that added together give a palindrome (24642).

The spelling of 86123781 in words is "eighty-six million, one hundred twenty-three thousand, seven hundred eighty-one".