1555143240 has 128 divisors (see below), whose sum is σ = 5422464000. Its totient is φ = 349425408.

The previous prime is 1555143223. The next prime is 1555143253. The reversal of 1555143240 is 423415551.

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 = 1555143198 and 1555143207.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 33871 + ... + 65249.

It is an arithmetic number, because the mean of its divisors is an integer number (42363000).

Almost surely, 2^1555143240 is an apocalyptic number.

1555143240 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 1555143240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2711232000).

1555143240 is an abundant number, since it is smaller than the sum of its proper divisors (3867320760).

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

1555143240 is a wasteful number, since it uses less digits than its factorization.

1555143240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31459 (or 31455 counting only the distinct ones).

The product of its (nonzero) digits is 12000, while the sum is 30.

The square root of 1555143240 is about 39435.3044872231. The cubic root of 1555143240 is about 1158.5731664022.

Adding to 1555143240 its reverse (423415551), we get a palindrome (1978558791).

The spelling of 1555143240 in words is "one billion, five hundred fifty-five million, one hundred forty-three thousand, two hundred forty".