326646781440 has 320 divisors, whose sum is σ = 1218828847104. Its totient is φ = 73073000448.

The previous prime is 326646781369. The next prime is 326646781441. The reversal of 326646781440 is 44187646623.

It is a tau number, because it is divible by the number of its divisors (320).

It is a super-2 number, since 2×326646781440² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (326646781441) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2462082 + ... + 2591358.

Almost surely, 2^326646781440 is an apocalyptic number.

326646781440 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 326646781440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (609414423552).

326646781440 is an abundant number, since it is smaller than the sum of its proper divisors (892182065664).

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

326646781440 is a wasteful number, since it uses less digits than its factorization.

326646781440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129357 (or 129341 counting only the distinct ones).

The product of its (nonzero) digits is 4644864, while the sum is 51.

The spelling of 326646781440 in words is "three hundred twenty-six billion, six hundred forty-six million, seven hundred eighty-one thousand, four hundred forty".