135221840640 has 864 divisors, whose sum is σ = 520692157440. Its totient is φ = 33480179712.

The previous prime is 135221840597. The next prime is 135221840647. The reversal of 135221840640 is 46048122531.

It is a happy number.

135221840640 is a `hidden beast` number, since 1 + 3 + 5 + 2 + 2 + 1 + 8 + 4 + 0 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (864).

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 = 135221840595 and 135221840604.

It is not an unprimeable number, because it can be changed into a prime (135221840647) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 565781641 + ... + 565781879.

It is an arithmetic number, because the mean of its divisors is an integer number (602652960).

Almost surely, 2^135221840640 is an apocalyptic number.

135221840640 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 135221840640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (260346078720).

135221840640 is an abundant number, since it is smaller than the sum of its proper divisors (385470316800).

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

135221840640 is a wasteful number, since it uses less digits than its factorization.

135221840640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 399 (or 373 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

The spelling of 135221840640 in words is "one hundred thirty-five billion, two hundred twenty-one million, eight hundred forty thousand, six hundred forty".