321538533120 has 1944 divisors, whose sum is σ = 1445168494224. Its totient is φ = 68223762432.

The previous prime is 321538533119. The next prime is 321538533161. The reversal of 321538533120 is 21335835123.

321538533120 is a `hidden beast` number, since 3 + 21 + 538 + 53 + 31 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (1944).

It is a super-2 number, since 2×321538533120² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 215 ways as a sum of consecutive naturals, for example, 4404637404 + ... + 4404637476.

Almost surely, 2^321538533120 is an apocalyptic number.

321538533120 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 321538533120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (722584247112).

321538533120 is an abundant number, since it is smaller than the sum of its proper divisors (1123629961104).

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

321538533120 is an equidigital number, since it uses as much as digits as its factorization.

321538533120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157 (or 107 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 36.

The spelling of 321538533120 in words is "three hundred twenty-one billion, five hundred thirty-eight million, five hundred thirty-three thousand, one hundred twenty".