1231509120 has 64 divisors (see below), whose sum is σ = 3925441440. Its totient is φ = 328401920.

The previous prime is 1231509119. The next prime is 1231509133. The reversal of 1231509120 is 219051321.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×1231509120² = 3033229425286348800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

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 7 ways as a sum of consecutive naturals, for example, 318786 + ... + 322625.

Almost surely, 2^1231509120 is an apocalyptic number.

1231509120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1231509120 is an abundant number, since it is smaller than the sum of its proper divisors (2693932320).

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

1231509120 is an equidigital number, since it uses as much as digits as its factorization.

1231509120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 641433 (or 641421 counting only the distinct ones).

The product of its (nonzero) digits is 540, while the sum is 24.

The square root of 1231509120 is about 35092.8642319204. The cubic root of 1231509120 is about 1071.8792839490.

The spelling of 1231509120 in words is "one billion, two hundred thirty-one million, five hundred nine thousand, one hundred twenty".