861893505792 has 576 divisors, whose sum is σ = 2862923857920. Its totient is φ = 253551513600.

The previous prime is 861893505773. The next prime is 861893505799. The reversal of 861893505792 is 297505398168.

861893505792 is a `hidden beast` number, since 8 + 6 + 1 + 8 + 9 + 3 + 50 + 579 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (576).

It is a super-3 number, since 3×861893505792³ (a number of 37 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (861893505799) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 361683033 + ... + 361685415.

It is an arithmetic number, because the mean of its divisors is an integer number (4970353920).

Almost surely, 2^861893505792 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 861893505792, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1431461928960).

861893505792 is an abundant number, since it is smaller than the sum of its proper divisors (2001030352128).

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

861893505792 is a wasteful number, since it uses less digits than its factorization.

861893505792 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2557 (or 2537 counting only the distinct ones).

The product of its (nonzero) digits is 32659200, while the sum is 63.

The spelling of 861893505792 in words is "eight hundred sixty-one billion, eight hundred ninety-three million, five hundred five thousand, seven hundred ninety-two".