851891040 has 768 divisors, whose sum is σ = 4023613440. Its totient is φ = 162570240.

The previous prime is 851891023. The next prime is 851891057. The reversal of 851891040 is 40198158.

It is an interprime number because it is at equal distance from previous prime (851891023) and next prime (851891057).

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

It is a junction number, because it is equal to n+sod(n) for n = 851890986 and 851891004.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 4324222 + ... + 4324418.

It is an arithmetic number, because the mean of its divisors is an integer number (5239080).

Almost surely, 2^851891040 is an apocalyptic number.

851891040 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 851891040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2011806720).

851891040 is an abundant number, since it is smaller than the sum of its proper divisors (3171722400).

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

851891040 is a wasteful number, since it uses less digits than its factorization.

851891040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252 (or 238 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 36.

The square root of 851891040 is about 29187.1725249295. The cubic root of 851891040 is about 947.9701961468.

The spelling of 851891040 in words is "eight hundred fifty-one million, eight hundred ninety-one thousand, forty".