850861520 has 80 divisors (see below), whose sum is σ = 2041275600. Its totient is φ = 329625600.

The previous prime is 850861513. The next prime is 850861541. The reversal of 850861520 is 25168058.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 560363584 + 290497936 = 23672^2 + 17044^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 487850 + ... + 489590.

It is an arithmetic number, because the mean of its divisors is an integer number (25515945).

Almost surely, 2^850861520 is an apocalyptic number.

850861520 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 850861520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1020637800).

850861520 is an abundant number, since it is smaller than the sum of its proper divisors (1190414080).

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

850861520 is a wasteful number, since it uses less digits than its factorization.

850861520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1944 (or 1938 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 35.

The square root of 850861520 is about 29169.5306784322. The cubic root of 850861520 is about 947.5881646251.

The spelling of 850861520 in words is "eight hundred fifty million, eight hundred sixty-one thousand, five hundred twenty".