851865120 has 192 divisors, whose sum is σ = 3078190080. Its totient is φ = 219801600.

The previous prime is 851865109. The next prime is 851865127. The reversal of 851865120 is 21568158.

It is a super-2 number, since 2×851865120² = 1451348365345228800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (851865127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 130740 + ... + 137100.

It is an arithmetic number, because the mean of its divisors is an integer number (16032240).

Almost surely, 2^851865120 is an apocalyptic number.

851865120 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 851865120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1539095040).

851865120 is an abundant number, since it is smaller than the sum of its proper divisors (2226324960).

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

851865120 is a wasteful number, since it uses less digits than its factorization.

851865120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6416 (or 6402 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 36.

The square root of 851865120 is about 29186.7284908741. The cubic root of 851865120 is about 947.9605816008.

The spelling of 851865120 in words is "eight hundred fifty-one million, eight hundred sixty-five thousand, one hundred twenty".