136640 has 56 divisors (see below), whose sum is σ = 377952. Its totient is φ = 46080.

The previous prime is 136621. The next prime is 136649. The reversal of 136640 is 46631.

It is a tau number, because it is divible by the number of its divisors (56).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 136640.

It is not an unprimeable number, because it can be changed into a prime (136649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2210 + ... + 2270.

2¹³⁶⁶⁴⁰ is an apocalyptic number.

136640 is a gapful number since it is divisible by the number (10) 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 136640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (188976).

136640 is an abundant number, since it is smaller than the sum of its proper divisors (241312).

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

136640 is an equidigital number, since it uses as much as digits as its factorization.

136640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85 (or 75 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 136640 is about 369.6484816687. The cubic root of 136640 is about 51.5061732632.

Subtracting from 136640 its reverse (46631), we obtain a palindrome (90009).

It can be divided in two parts, 13 and 6640, that multiplied together give a triangular number (86320 = T₄₁₅).

The spelling of 136640 in words is "one hundred thirty-six thousand, six hundred forty".