861155367072 has 1728 divisors, whose sum is σ = 3361258736640. Its totient is φ = 190207180800.

The previous prime is 861155367029. The next prime is 861155367073. The reversal of 861155367072 is 270763551168.

It is a super-2 number, since 2×861155367072² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861155367073) 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 287 ways as a sum of consecutive naturals, for example, 11796648828 + ... + 11796648900.

It is an arithmetic number, because the mean of its divisors is an integer number (1945172880).

Almost surely, 2^861155367072 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 861155367072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1680629368320).

861155367072 is an abundant number, since it is smaller than the sum of its proper divisors (2500103369568).

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

861155367072 is a wasteful number, since it uses less digits than its factorization.

861155367072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 227 (or 199 counting only the distinct ones).

The product of its (nonzero) digits is 2116800, while the sum is 51.

The spelling of 861155367072 in words is "eight hundred sixty-one billion, one hundred fifty-five million, three hundred sixty-seven thousand, seventy-two".