135865638 has 48 divisors (see below), whose sum is σ = 311659920. Its totient is φ = 42702912.

The previous prime is 135865633. The next prime is 135865651. The reversal of 135865638 is 836568531.

135865638 is a `hidden beast` number, since 1 + 3 + 5 + 8 + 6 + 5 + 638 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 135865593 and 135865602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (135865633) 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, 19420 + ... + 25472.

It is an arithmetic number, because the mean of its divisors is an integer number (6492915).

Almost surely, 2^135865638 is an apocalyptic number.

135865638 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 135865638, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (155829960).

135865638 is an abundant number, since it is smaller than the sum of its proper divisors (175794282).

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

135865638 is a wasteful number, since it uses less digits than its factorization.

135865638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6133 (or 6130 counting only the distinct ones).

The product of its digits is 518400, while the sum is 45.

The square root of 135865638 is about 11656.1416429280. The cubic root of 135865638 is about 514.0869081447.

It can be divided in two parts, 135865 and 638, that added together give a triangular number (136503 = T₅₂₂).

The spelling of 135865638 in words is "one hundred thirty-five million, eight hundred sixty-five thousand, six hundred thirty-eight".