321978240 has 160 divisors (see below), whose sum is σ = 1150027560. Its totient is φ = 85847040.

The previous prime is 321978229. The next prime is 321978277. The reversal of 321978240 is 42879123.

321978240 is a `hidden beast` number, since 321 + 97 + 8 + 240 = 666.

It is a tau number, because it is divible by the number of its divisors (160).

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 = 321978195 and 321978204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 48735 + ... + 54945.

Almost surely, 2^321978240 is an apocalyptic number.

321978240 is a gapful number since it is divisible by the number (30) 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 321978240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (575013780).

321978240 is an abundant number, since it is smaller than the sum of its proper divisors (828049320).

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

321978240 is an equidigital number, since it uses as much as digits as its factorization.

321978240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6242 (or 6221 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 321978240 is about 17943.7521159873. The cubic root of 321978240 is about 685.3969603180.

The spelling of 321978240 in words is "three hundred twenty-one million, nine hundred seventy-eight thousand, two hundred forty".