861132809680 has 240 divisors, whose sum is σ = 2372007088080. Its totient is φ = 288804003840.

The previous prime is 861132809657. The next prime is 861132809687. The reversal of 861132809680 is 86908231168.

It can be written as a sum of positive squares in 8 ways, for example, as 26920933776 + 834211875904 = 164076^2 + 913352^2 .

It is a super-2 number, since 2×861132809680² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (52).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861132809687) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 202474434 + ... + 202478686.

It is an arithmetic number, because the mean of its divisors is an integer number (9883362867).

Almost surely, 2^861132809680 is an apocalyptic number.

861132809680 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 861132809680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1186003544040).

861132809680 is an abundant number, since it is smaller than the sum of its proper divisors (1510874278400).

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

861132809680 is a wasteful number, since it uses less digits than its factorization.

861132809680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5910 (or 5893 counting only the distinct ones).

The product of its (nonzero) digits is 995328, while the sum is 52.

The spelling of 861132809680 in words is "eight hundred sixty-one billion, one hundred thirty-two million, eight hundred nine thousand, six hundred eighty".