861039178272 has 1152 divisors, whose sum is σ = 3359446272000. Its totient is φ = 214970692608.

The previous prime is 861039178211. The next prime is 861039178277. The reversal of 861039178272 is 272871930168.

It is a happy number.

861039178272 is a `hidden beast` number, since 8 + 610 + 3 + 9 + 17 + 8 + 2 + 7 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (861039178277) 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 191 ways as a sum of consecutive naturals, for example, 658789843 + ... + 658791149.

It is an arithmetic number, because the mean of its divisors is an integer number (2916186000).

Almost surely, 2^861039178272 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 861039178272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1679723136000).

861039178272 is an abundant number, since it is smaller than the sum of its proper divisors (2498407093728).

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

861039178272 is a wasteful number, since it uses less digits than its factorization.

861039178272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1385 (or 1351 counting only the distinct ones).

The product of its (nonzero) digits is 2032128, while the sum is 54.

The spelling of 861039178272 in words is "eight hundred sixty-one billion, thirty-nine million, one hundred seventy-eight thousand, two hundred seventy-two".