1531145220 has 48 divisors (see below), whose sum is σ = 4676954688. Its totient is φ = 371186560.

The previous prime is 1531145207. The next prime is 1531145257. The reversal of 1531145220 is 225411351.

It is a happy number.

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 15 ways as a sum of consecutive naturals, for example, 1159299 + ... + 1160618.

It is an arithmetic number, because the mean of its divisors is an integer number (97436556).

Almost surely, 2^1531145220 is an apocalyptic number.

1531145220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1531145220 is an abundant number, since it is smaller than the sum of its proper divisors (3145809468).

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

1531145220 is a wasteful number, since it uses less digits than its factorization.

1531145220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2319940 (or 2319938 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 24.

The square root of 1531145220 is about 39129.8507536126. The cubic root of 1531145220 is about 1152.5827822645.

Adding to 1531145220 its reverse (225411351), we get a palindrome (1756556571).

The spelling of 1531145220 in words is "one billion, five hundred thirty-one million, one hundred forty-five thousand, two hundred twenty".