86840640 has 336 divisors, whose sum is σ = 337108800. Its totient is φ = 20984832.

The previous prime is 86840609. The next prime is 86840647. The reversal of 86840640 is 4604868.

86840640 is a `hidden beast` number, since 8 + 6 + 8 + 4 + 0 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 86840595 and 86840604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (86840647) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3775669 + ... + 3775691.

It is an arithmetic number, because the mean of its divisors is an integer number (1003300).

Almost surely, 2^86840640 is an apocalyptic number.

86840640 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 86840640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (168554400).

86840640 is an abundant number, since it is smaller than the sum of its proper divisors (250268160).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

86840640 is a wasteful number, since it uses less digits than its factorization.

86840640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91 (or 52 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 36.

The square root of 86840640 is about 9318.8325449060. The cubic root of 86840640 is about 442.8340482481.

The spelling of 86840640 in words is "eighty-six million, eight hundred forty thousand, six hundred forty".