1531220220 has 48 divisors (see below), whose sum is σ = 4763797920. Its totient is φ = 408325248.

The previous prime is 1531220143. The next prime is 1531220221. The reversal of 1531220220 is 220221351.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 1531220193 and 1531220202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1531220221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1417257 + ... + 1418336.

It is an arithmetic number, because the mean of its divisors is an integer number (99245790).

Almost surely, 2^1531220220 is an apocalyptic number.

1531220220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1531220220 is an abundant number, since it is smaller than the sum of its proper divisors (3232577700).

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

1531220220 is a wasteful number, since it uses less digits than its factorization.

1531220220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2835611 (or 2835603 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 1531220220 is about 39130.8090895141. The cubic root of 1531220220 is about 1152.6016009230.

Adding to 1531220220 its reverse (220221351), we get a palindrome (1751441571).

The spelling of 1531220220 in words is "one billion, five hundred thirty-one million, two hundred twenty thousand, two hundred twenty".