1556605020 has 96 divisors (see below), whose sum is σ = 4630348800. Its totient is φ = 389608704.

The previous prime is 1556605013. The next prime is 1556605021. The reversal of 1556605020 is 205066551.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1556605021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 117997 + ... + 130523.

It is an arithmetic number, because the mean of its divisors is an integer number (48232800).

Almost surely, 2^1556605020 is an apocalyptic number.

1556605020 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 1556605020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2315174400).

1556605020 is an abundant number, since it is smaller than the sum of its proper divisors (3073743780).

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

1556605020 is a wasteful number, since it uses less digits than its factorization.

1556605020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12667 (or 12665 counting only the distinct ones).

The product of its (nonzero) digits is 9000, while the sum is 30.

The square root of 1556605020 is about 39453.8340342228. The cubic root of 1556605020 is about 1158.9360587459.

The spelling of 1556605020 in words is "one billion, five hundred fifty-six million, six hundred five thousand, twenty".