321543640 has 32 divisors (see below), whose sum is σ = 789244560. Its totient is φ = 116924800.

The previous prime is 321543583. The next prime is 321543659. The reversal of 321543640 is 46345123.

321543640 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 321543599 and 321543608.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 364951 + ... + 365830.

Almost surely, 2^321543640 is an apocalyptic number.

It is an amenable number.

321543640 is an abundant number, since it is smaller than the sum of its proper divisors (467700920).

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

321543640 is a wasteful number, since it uses less digits than its factorization.

321543640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 730803 (or 730799 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 28.

The square root of 321543640 is about 17931.6379619933. The cubic root of 321543640 is about 685.0884429465.

Adding to 321543640 its reverse (46345123), we get a palindrome (367888763).

The spelling of 321543640 in words is "three hundred twenty-one million, five hundred forty-three thousand, six hundred forty".