135221020 has 48 divisors (see below), whose sum is σ = 315651168. Its totient is φ = 48239360.

The previous prime is 135220973. The next prime is 135221033. The reversal of 135221020 is 20122531.

135221020 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 135220985 and 135221003.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5862 + ... + 17458.

It is an arithmetic number, because the mean of its divisors is an integer number (6576066).

Almost surely, 2^135221020 is an apocalyptic number.

135221020 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 135221020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (157825584).

135221020 is an abundant number, since it is smaller than the sum of its proper divisors (180430148).

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

135221020 is a wasteful number, since it uses less digits than its factorization.

135221020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11670 (or 11668 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 135221020 is about 11628.4573353476. The cubic root of 135221020 is about 513.2725860913.

Adding to 135221020 its reverse (20122531), we get a palindrome (155343551).

The spelling of 135221020 in words is "one hundred thirty-five million, two hundred twenty-one thousand, twenty".