321399960 has 256 divisors, whose sum is σ = 1186928640. Its totient is φ = 67952640.

The previous prime is 321399941. The next prime is 321399973. The reversal of 321399960 is 69993123.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1013722 + ... + 1014038.

It is an arithmetic number, because the mean of its divisors is an integer number (4636440).

Almost surely, 2^321399960 is an apocalyptic number.

321399960 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 321399960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (593464320).

321399960 is an abundant number, since it is smaller than the sum of its proper divisors (865528680).

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

321399960 is a wasteful number, since it uses less digits than its factorization.

321399960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 426 (or 422 counting only the distinct ones).

The product of its (nonzero) digits is 78732, while the sum is 42.

The square root of 321399960 is about 17927.6311876388. The cubic root of 321399960 is about 684.9863850811.

The spelling of 321399960 in words is "three hundred twenty-one million, three hundred ninety-nine thousand, nine hundred sixty".