135720 has 96 divisors (see below), whose sum is σ = 491400. Its totient is φ = 32256.

The previous prime is 135719. The next prime is 135721. The reversal of 135720 is 27531.

It is an interprime number because it is at equal distance from previous prime (135719) and next prime (135721).

It can be written as a sum of positive squares in 4 ways, for example, as 86436 + 49284 = 294^2 + 222^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nialpdrome in base 12.

It is a junction number, because it is equal to n+sod(n) for n = 135693 and 135702.

It is not an unprimeable number, because it can be changed into a prime (135721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4666 + ... + 4694.

2¹³⁵⁷²⁰ is an apocalyptic number.

135720 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 135720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (245700).

135720 is an abundant number, since it is smaller than the sum of its proper divisors (355680).

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

135720 is a wasteful number, since it uses less digits than its factorization.

135720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59 (or 52 counting only the distinct ones).

The product of its (nonzero) digits is 210, while the sum is 18.

The square root of 135720 is about 368.4019543922. The cubic root of 135720 is about 51.3903154651.

It can be divided in two parts, 1 and 35720, that added together give a square (35721 = 189²).

The spelling of 135720 in words is "one hundred thirty-five thousand, seven hundred twenty".