135861 has 16 divisors (see below), whose sum is σ = 207360. Its totient is φ = 78320.

The previous prime is 135859. The next prime is 135887. The reversal of 135861 is 168531.

It is not a de Polignac number, because 135861 - 2¹ = 135859 is a prime.

It is a super-2 number, since 2×135861² = 36916422642, which contains 22 as substring.

It is a Curzon number.

It is a plaindrome in base 13.

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 135861.

It is not an unprimeable number, because it can be changed into a prime (135841) 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, 670 + ... + 848.

It is an arithmetic number, because the mean of its divisors is an integer number (12960).

2¹³⁵⁸⁶¹ is an apocalyptic number.

135861 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

135861 is a deficient number, since it is larger than the sum of its proper divisors (71499).

135861 is a wasteful number, since it uses less digits than its factorization.

135861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216.

The product of its digits is 720, while the sum is 24.

The square root of 135861 is about 368.5932717780. The cubic root of 135861 is about 51.4081058340.

The spelling of 135861 in words is "one hundred thirty-five thousand, eight hundred sixty-one".