155511540 has 72 divisors (see below), whose sum is σ = 480648168. Its totient is φ = 40684800.

The previous prime is 155511527. The next prime is 155511557. The reversal of 155511540 is 45115551.

155511540 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 53056656 + 102454884 = 7284^2 + 10122^2 .

It is a congruent number.

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, 1390 + ... + 17690.

It is an arithmetic number, because the mean of its divisors is an integer number (6675669).

Almost surely, 2^155511540 is an apocalyptic number.

155511540 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 155511540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (240324084).

155511540 is an abundant number, since it is smaller than the sum of its proper divisors (325136628).

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

155511540 is a wasteful number, since it uses less digits than its factorization.

155511540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16369 (or 16364 counting only the distinct ones).

The product of its (nonzero) digits is 2500, while the sum is 27.

The square root of 155511540 is about 12470.4266165998. The cubic root of 155511540 is about 537.7588182053.

The spelling of 155511540 in words is "one hundred fifty-five million, five hundred eleven thousand, five hundred forty".