861001120512 has 432 divisors, whose sum is σ = 2979717118560. Its totient is φ = 236213895168.

The previous prime is 861001120501. The next prime is 861001120513. The reversal of 861001120512 is 215021100168.

861001120512 is a `hidden beast` number, since 8 + 610 + 0 + 11 + 20 + 5 + 12 = 666.

It is not an unprimeable number, because it can be changed into a prime (861001120513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 9629998 + ... + 9718994.

It is an arithmetic number, because the mean of its divisors is an integer number (6897493330).

Almost surely, 2^861001120512 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 861001120512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1489858559280).

861001120512 is an abundant number, since it is smaller than the sum of its proper divisors (2118715998048).

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

861001120512 is a wasteful number, since it uses less digits than its factorization.

861001120512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89068 (or 89051 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 27.

The spelling of 861001120512 in words is "eight hundred sixty-one billion, one million, one hundred twenty thousand, five hundred twelve".