1531220240 has 80 divisors (see below), whose sum is σ = 3890483136. Its totient is φ = 555840000.

The previous prime is 1531220227. The next prime is 1531220263. The reversal of 1531220240 is 420221351.

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

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 679115 + ... + 681365.

Almost surely, 2^1531220240 is an apocalyptic number.

1531220240 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 1531220240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1945241568).

1531220240 is an abundant number, since it is smaller than the sum of its proper divisors (2359262896).

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

1531220240 is a wasteful number, since it uses less digits than its factorization.

1531220240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3048 (or 3042 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 1531220240 is about 39130.8093450672. The cubic root of 1531220240 is about 1152.6016059413.

Adding to 1531220240 its reverse (420221351), we get a palindrome (1951441591).

The spelling of 1531220240 in words is "one billion, five hundred thirty-one million, two hundred twenty thousand, two hundred forty".