861599385600 has 576 divisors, whose sum is σ = 3034200798720. Its totient is φ = 214931865600.

The previous prime is 861599385599. The next prime is 861599385611. The reversal of 861599385600 is 6583995168.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 472626289 + ... + 472628111.

It is an arithmetic number, because the mean of its divisors is an integer number (5267709720).

Almost surely, 2^861599385600 is an apocalyptic number.

861599385600 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 861599385600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1517100399360).

861599385600 is an abundant number, since it is smaller than the sum of its proper divisors (2172601413120).

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

861599385600 is a wasteful number, since it uses less digits than its factorization.

861599385600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2056 (or 2031 counting only the distinct ones).

The product of its (nonzero) digits is 13996800, while the sum is 60.

The spelling of 861599385600 in words is "eight hundred sixty-one billion, five hundred ninety-nine million, three hundred eighty-five thousand, six hundred".