861728845824 has 936 divisors, whose sum is σ = 3262979865600. Its totient is φ = 216450662400.

The previous prime is 861728845799. The next prime is 861728845837. The reversal of 861728845824 is 428548827168.

861728845824 is a `hidden beast` number, since 8 + 6 + 172 + 8 + 8 + 458 + 2 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 615959877 + ... + 615961275.

It is an arithmetic number, because the mean of its divisors is an integer number (3486089600).

Almost surely, 2^861728845824 is an apocalyptic number.

861728845824 is a gapful number since it is divisible by the number (84) 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 861728845824, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1631489932800).

861728845824 is an abundant number, since it is smaller than the sum of its proper divisors (2401251019776).

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

861728845824 is a wasteful number, since it uses less digits than its factorization.

861728845824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1485 (or 1453 counting only the distinct ones).

The product of its digits is 55050240, while the sum is 63.

The spelling of 861728845824 in words is "eight hundred sixty-one billion, seven hundred twenty-eight million, eight hundred forty-five thousand, eight hundred twenty-four".