135188640 has 144 divisors (see below), whose sum is σ = 464373000. Its totient is φ = 35813376.

The previous prime is 135188611. The next prime is 135188663. The reversal of 135188640 is 46881531.

135188640 is a `hidden beast` number, since 1 + 3 + 5 + 1 + 8 + 8 + 640 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 91470096 + 43718544 = 9564^2 + 6612^2 .

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

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 = 135188595 and 135188604.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 387186 + ... + 387534.

Almost surely, 2^135188640 is an apocalyptic number.

135188640 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 135188640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (232186500).

135188640 is an abundant number, since it is smaller than the sum of its proper divisors (329184360).

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

135188640 is a wasteful number, since it uses less digits than its factorization.

135188640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 639 (or 628 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 135188640 is about 11627.0649778867. The cubic root of 135188640 is about 513.2316134350.

The spelling of 135188640 in words is "one hundred thirty-five million, one hundred eighty-eight thousand, six hundred forty".