1231009920 has 256 divisors, whose sum is σ = 4983148800. Its totient is φ = 281346048.

The previous prime is 1231009903. The next prime is 1231009931. The reversal of 1231009920 is 299001321.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 115872 + ... + 126048.

It is an arithmetic number, because the mean of its divisors is an integer number (19465425).

Almost surely, 2^1231009920 is an apocalyptic number.

1231009920 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 1231009920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2491574400).

1231009920 is an abundant number, since it is smaller than the sum of its proper divisors (3752138880).

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

1231009920 is a wasteful number, since it uses less digits than its factorization.

1231009920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10212 (or 10194 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 27.

The square root of 1231009920 is about 35085.7509539129. The cubic root of 1231009920 is about 1071.7344333627.

The spelling of 1231009920 in words is "one billion, two hundred thirty-one million, nine thousand, nine hundred twenty".