1555220240 has 80 divisors (see below), whose sum is σ = 4137794688. Its totient is φ = 532528128.

The previous prime is 1555220179. The next prime is 1555220263. The reversal of 1555220240 is 420225551.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 627644 + ... + 630116.

Almost surely, 2^1555220240 is an apocalyptic number.

1555220240 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 1555220240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2068897344).

1555220240 is an abundant number, since it is smaller than the sum of its proper divisors (2582574448).

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

1555220240 is a wasteful number, since it uses less digits than its factorization.

1555220240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3616 (or 3610 counting only the distinct ones).

The product of its (nonzero) digits is 4000, while the sum is 26.

The square root of 1555220240 is about 39436.2807576982. The cubic root of 1555220240 is about 1158.5922876122.

Adding to 1555220240 its reverse (420225551), we get a palindrome (1975445791).

The spelling of 1555220240 in words is "one billion, five hundred fifty-five million, two hundred twenty thousand, two hundred forty".