981231840 has 384 divisors, whose sum is σ = 3762339840. Its totient is φ = 237772800.

The previous prime is 981231833. The next prime is 981231841. The reversal of 981231840 is 48132189.

981231840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 981231795 and 981231804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (981231841) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2276425 + ... + 2276855.

It is an arithmetic number, because the mean of its divisors is an integer number (9797760).

Almost surely, 2^981231840 is an apocalyptic number.

981231840 is a gapful number since it is divisible by the number (90) 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 981231840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1881169920).

981231840 is an abundant number, since it is smaller than the sum of its proper divisors (2781108000).

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

981231840 is a wasteful number, since it uses less digits than its factorization.

981231840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 503 (or 489 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 981231840 is about 31324.6203488566. The cubic root of 981231840 is about 993.7043952016.

The spelling of 981231840 in words is "nine hundred eighty-one million, two hundred thirty-one thousand, eight hundred forty".