155511020 has 96 divisors (see below), whose sum is σ = 386588160. Its totient is φ = 51448320.

The previous prime is 155511011. The next prime is 155511023. The reversal of 155511020 is 20115551.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 155510983 and 155511001.

It is not an unprimeable number, because it can be changed into a prime (155511023) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 553280 + ... + 553560.

It is an arithmetic number, because the mean of its divisors is an integer number (4026960).

Almost surely, 2^155511020 is an apocalyptic number.

155511020 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 155511020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (193294080).

155511020 is an abundant number, since it is smaller than the sum of its proper divisors (231077140).

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

155511020 is a wasteful number, since it uses less digits than its factorization.

155511020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 423 (or 421 counting only the distinct ones).

The product of its (nonzero) digits is 250, while the sum is 20.

The square root of 155511020 is about 12470.4057672555. The cubic root of 155511020 is about 537.7582188180.

Adding to 155511020 its reverse (20115551), we get a palindrome (175626571).

The spelling of 155511020 in words is "one hundred fifty-five million, five hundred eleven thousand, twenty".