1231231520 has 24 divisors (see below), whose sum is σ = 2908784844. Its totient is φ = 492492544.

The previous prime is 1231231489. The next prime is 1231231531. The reversal of 1231231520 is 251321321.

It can be written as a sum of positive squares in 2 ways, for example, as 1111022224 + 120209296 = 33332^2 + 10964^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 1231231492 and 1231231501.

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 3 ways as a sum of consecutive naturals, for example, 3847439 + ... + 3847758.

Almost surely, 2^1231231520 is an apocalyptic number.

1231231520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1231231520 is an abundant number, since it is smaller than the sum of its proper divisors (1677553324).

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

1231231520 is an equidigital number, since it uses as much as digits as its factorization.

1231231520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7695212 (or 7695204 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 1231231520 is about 35088.9087889607. The cubic root of 1231231520 is about 1071.7987388561.

Adding to 1231231520 its reverse (251321321), we get a palindrome (1482552841).

The spelling of 1231231520 in words is "one billion, two hundred thirty-one million, two hundred thirty-one thousand, five hundred twenty".