856320491520 has 840 divisors, whose sum is σ = 3321277799616. Its totient is φ = 210595479552.

The previous prime is 856320491501. The next prime is 856320491531. The reversal of 856320491520 is 25194023658.

856320491520 is a `hidden beast` number, since 8 + 5 + 6 + 32 + 0 + 4 + 91 + 520 = 666.

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 55 ways as a sum of consecutive naturals, for example, 776355289 + ... + 776356391.

Almost surely, 2^856320491520 is an apocalyptic number.

856320491520 is a gapful number since it is divisible by the number (80) 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 856320491520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1660638899808).

856320491520 is an abundant number, since it is smaller than the sum of its proper divisors (2464957308096).

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

856320491520 is an equidigital number, since it uses as much as digits as its factorization.

856320491520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1167 (or 1126 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 45.

The spelling of 856320491520 in words is "eight hundred fifty-six billion, three hundred twenty million, four hundred ninety-one thousand, five hundred twenty".