321961640 has 384 divisors, whose sum is σ = 1061786880. Its totient is φ = 85155840.

The previous prime is 321961603. The next prime is 321961649. The reversal of 321961640 is 46169123.

It is a junction number, because it is equal to n+sod(n) for n = 321961597 and 321961606.

It is not an unprimeable number, because it can be changed into a prime (321961649) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 7487459 + ... + 7487501.

It is an arithmetic number, because the mean of its divisors is an integer number (2765070).

Almost surely, 2^321961640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 321961640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (530893440).

321961640 is an abundant number, since it is smaller than the sum of its proper divisors (739825240).

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

321961640 is a wasteful number, since it uses less digits than its factorization.

321961640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113 (or 98 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 321961640 is about 17943.2895534793. The cubic root of 321961640 is about 685.3851812766.

The spelling of 321961640 in words is "three hundred twenty-one million, nine hundred sixty-one thousand, six hundred forty".