856651520 has 72 divisors (see below), whose sum is σ = 2118238080. Its totient is φ = 331591680.

The previous prime is 856651517. The next prime is 856651541. The reversal of 856651520 is 25156658.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28886 + ... + 50474.

Almost surely, 2^856651520 is an apocalyptic number.

856651520 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 856651520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1059119040).

856651520 is an abundant number, since it is smaller than the sum of its proper divisors (1261586560).

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

856651520 is a wasteful number, since it uses less digits than its factorization.

856651520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21641 (or 21627 counting only the distinct ones).

The product of its (nonzero) digits is 72000, while the sum is 38.

The square root of 856651520 is about 29268.6098064121. The cubic root of 856651520 is about 949.7327115074.

The spelling of 856651520 in words is "eight hundred fifty-six million, six hundred fifty-one thousand, five hundred twenty".