321716640 has 288 divisors, whose sum is σ = 1217414016. Its totient is φ = 69949440.

The previous prime is 321716639. The next prime is 321716641. The reversal of 321716640 is 46617123.

It is an interprime number because it is at equal distance from previous prime (321716639) and next prime (321716641).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 321716598 and 321716607.

It is not an unprimeable number, because it can be changed into a prime (321716641) 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, 1777350 + ... + 1777530.

It is an arithmetic number, because the mean of its divisors is an integer number (4227132).

Almost surely, 2^321716640 is an apocalyptic number.

321716640 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 321716640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (608707008).

321716640 is an abundant number, since it is smaller than the sum of its proper divisors (895697376).

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

321716640 is a wasteful number, since it uses less digits than its factorization.

321716640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252 (or 221 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 30.

The square root of 321716640 is about 17936.4611894320. The cubic root of 321716640 is about 685.2112868744.

The spelling of 321716640 in words is "three hundred twenty-one million, seven hundred sixteen thousand, six hundred forty".