155420440 has 32 divisors (see below), whose sum is σ = 399653280. Its totient is φ = 53286912.

The previous prime is 155420383. The next prime is 155420459. The reversal of 155420440 is 44024551.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 277257 + ... + 277816.

It is an arithmetic number, because the mean of its divisors is an integer number (12489165).

Almost surely, 2^155420440 is an apocalyptic number.

155420440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

155420440 is an abundant number, since it is smaller than the sum of its proper divisors (244232840).

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

155420440 is a wasteful number, since it uses less digits than its factorization.

155420440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 555091 (or 555087 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 25.

The square root of 155420440 is about 12466.7734398280. The cubic root of 155420440 is about 537.6537897774.

Adding to 155420440 its reverse (44024551), we get a palindrome (199444991).

The spelling of 155420440 in words is "one hundred fifty-five million, four hundred twenty thousand, four hundred forty".