1555433220 has 96 divisors (see below), whose sum is σ = 4790653056. Its totient is φ = 377055360.

The previous prime is 1555433219. The next prime is 1555433237. The reversal of 1555433220 is 223345551.

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

It is an unprimeable number.

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, 70122 + ... + 89598.

It is an arithmetic number, because the mean of its divisors is an integer number (49902636).

Almost surely, 2^1555433220 is an apocalyptic number.

1555433220 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 1555433220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2395326528).

1555433220 is an abundant number, since it is smaller than the sum of its proper divisors (3235219836).

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

1555433220 is a wasteful number, since it uses less digits than its factorization.

1555433220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19522 (or 19498 counting only the distinct ones).

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

The square root of 1555433220 is about 39438.9809706083. The cubic root of 1555433220 is about 1158.6451730956.

Adding to 1555433220 its reverse (223345551), we get a palindrome (1778778771).

The spelling of 1555433220 in words is "one billion, five hundred fifty-five million, four hundred thirty-three thousand, two hundred twenty".