321740640 has 384 divisors, whose sum is σ = 1287861120. Its totient is φ = 74317824.

The previous prime is 321740611. The next prime is 321740677. The reversal of 321740640 is 46047123.

321740640 is a `hidden beast` number, since 3 + 2 + 17 + 4 + 0 + 640 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 954552 + ... + 954888.

It is an arithmetic number, because the mean of its divisors is an integer number (3353805).

Almost surely, 2^321740640 is an apocalyptic number.

321740640 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 321740640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (643930560).

321740640 is an abundant number, since it is smaller than the sum of its proper divisors (966120480).

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

321740640 is a wasteful number, since it uses less digits than its factorization.

321740640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 391 (or 377 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 27.

The square root of 321740640 is about 17937.1302052474. The cubic root of 321740640 is about 685.2283253279.

Adding to 321740640 its reverse (46047123), we get a palindrome (367787763).

The spelling of 321740640 in words is "three hundred twenty-one million, seven hundred forty thousand, six hundred forty".