320531613660 has 144 divisors (see below), whose sum is σ = 978704004096. Its totient is φ = 84910928256.

The previous prime is 320531613643. The next prime is 320531613671. The reversal of 320531613660 is 66316135023.

320531613660 is a `hidden beast` number, since 3 + 2 + 0 + 5 + 31 + 613 + 6 + 6 + 0 = 666.

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 47 ways as a sum of consecutive naturals, for example, 87983799 + ... + 87987441.

It is an arithmetic number, because the mean of its divisors is an integer number (6796555584).

Almost surely, 2^320531613660 is an apocalyptic number.

320531613660 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 320531613660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (489352002048).

320531613660 is an abundant number, since it is smaller than the sum of its proper divisors (658172390436).

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

320531613660 is a wasteful number, since it uses less digits than its factorization.

320531613660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6752 (or 6747 counting only the distinct ones).

The product of its (nonzero) digits is 58320, while the sum is 36.

Adding to 320531613660 its reverse (66316135023), we get a palindrome (386847748683).

The spelling of 320531613660 in words is "three hundred twenty billion, five hundred thirty-one million, six hundred thirteen thousand, six hundred sixty".