155533440 has 128 divisors (see below), whose sum is σ = 504532800. Its totient is φ = 40742912.

The previous prime is 155533439. The next prime is 155533453. The reversal of 155533440 is 44335551.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 155533398 and 155533407.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 112594 + ... + 113966.

Almost surely, 2^155533440 is an apocalyptic number.

155533440 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 155533440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (252266400).

155533440 is an abundant number, since it is smaller than the sum of its proper divisors (348999360).

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

155533440 is a wasteful number, since it uses less digits than its factorization.

155533440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1454 (or 1442 counting only the distinct ones).

The product of its (nonzero) digits is 18000, while the sum is 30.

The square root of 155533440 is about 12471.3046631056. The cubic root of 155533440 is about 537.7840604163.

Adding to 155533440 its reverse (44335551), we get a palindrome (199868991).

The spelling of 155533440 in words is "one hundred fifty-five million, five hundred thirty-three thousand, four hundred forty".