155405440 has 64 divisors (see below), whose sum is σ = 380223360. Its totient is φ = 60705792.

The previous prime is 155405423. The next prime is 155405447. The reversal of 155405440 is 44504551.

It is a tau number, because it is divible by the number of its divisors (64).

It is a junction number, because it is equal to n+sod(n) for n = 155405399 and 155405408.

It is not an unprimeable number, because it can be changed into a prime (155405447) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24697 + ... + 30343.

It is an arithmetic number, because the mean of its divisors is an integer number (5940990).

Almost surely, 2^155405440 is an apocalyptic number.

155405440 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 155405440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (190111680).

155405440 is an abundant number, since it is smaller than the sum of its proper divisors (224817920).

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

155405440 is an equidigital number, since it uses as much as digits as its factorization.

155405440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5709 (or 5697 counting only the distinct ones).

The product of its (nonzero) digits is 8000, while the sum is 28.

The square root of 155405440 is about 12466.1718261863. The cubic root of 155405440 is about 537.6364924680.

Adding to 155405440 its reverse (44504551), we get a palindrome (199909991).

The spelling of 155405440 in words is "one hundred fifty-five million, four hundred five thousand, four hundred forty".