321532640 has 288 divisors, whose sum is σ = 956261376. Its totient is φ = 101038080.

The previous prime is 321532597. The next prime is 321532643. The reversal of 321532640 is 46235123.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (321532643) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6841097 + ... + 6841143.

It is an arithmetic number, because the mean of its divisors is an integer number (3320352).

Almost surely, 2^321532640 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 321532640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (478130688).

321532640 is an abundant number, since it is smaller than the sum of its proper divisors (634728736).

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

321532640 is a wasteful number, since it uses less digits than its factorization.

321532640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122 (or 101 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 26.

The square root of 321532640 is about 17931.3312389237. The cubic root of 321532640 is about 685.0806305712.

Adding to 321532640 its reverse (46235123), we get a palindrome (367767763).

The spelling of 321532640 in words is "three hundred twenty-one million, five hundred thirty-two thousand, six hundred forty".