320709517920 has 1152 divisors, whose sum is σ = 1321124732928. Its totient is φ = 69938380800.

The previous prime is 320709517907. The next prime is 320709517967. The reversal of 320709517920 is 29715907023.

320709517920 is a `hidden beast` number, since 320 + 70 + 95 + 179 + 2 + 0 = 666.

It is a super-2 number, since 2×320709517920² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 859810854 + ... + 859811226.

It is an arithmetic number, because the mean of its divisors is an integer number (1146809664).

Almost surely, 2^320709517920 is an apocalyptic number.

320709517920 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 320709517920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (660562366464).

320709517920 is an abundant number, since it is smaller than the sum of its proper divisors (1000415215008).

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

320709517920 is a wasteful number, since it uses less digits than its factorization.

320709517920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 556 (or 545 counting only the distinct ones).

The product of its (nonzero) digits is 238140, while the sum is 45.

The spelling of 320709517920 in words is "three hundred twenty billion, seven hundred nine million, five hundred seventeen thousand, nine hundred twenty".