135663840 has 144 divisors (see below), whose sum is σ = 498633408. Its totient is φ = 33389568.

The previous prime is 135663799. The next prime is 135663841. The reversal of 135663840 is 48366531.

135663840 is a `hidden beast` number, since 13 + 5 + 6 + 638 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-3 number, since 3×135663840³ (a number of 25 digits) contains 333 as substring.

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 = 135663795 and 135663804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (135663841) 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, 15097 + ... + 22343.

It is an arithmetic number, because the mean of its divisors is an integer number (3462732).

Almost surely, 2^135663840 is an apocalyptic number.

135663840 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 135663840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (249316704).

135663840 is an abundant number, since it is smaller than the sum of its proper divisors (362969568).

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

135663840 is a wasteful number, since it uses less digits than its factorization.

135663840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7281 (or 7270 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The square root of 135663840 is about 11647.4821313450. The cubic root of 135663840 is about 513.8322616779.

It can be divided in two parts, 135663 and 840, that added together give a triangular number (136503 = T₅₂₂).

The spelling of 135663840 in words is "one hundred thirty-five million, six hundred sixty-three thousand, eight hundred forty".