861785555540 has 48 divisors (see below), whose sum is σ = 2227384209792. Its totient is φ = 272740922496.

The previous prime is 861785555539. The next prime is 861785555551. The reversal of 861785555540 is 45555587168.

It is a self number, because there is not a number n which added to its sum of digits gives 861785555540.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 236752454 + ... + 236756093.

It is an arithmetic number, because the mean of its divisors is an integer number (46403837704).

Almost surely, 2^861785555540 is an apocalyptic number.

It is an amenable number.

861785555540 is an abundant number, since it is smaller than the sum of its proper divisors (1365598654252).

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

861785555540 is a wasteful number, since it uses less digits than its factorization.

861785555540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 473508576 (or 473508574 counting only the distinct ones).

The product of its (nonzero) digits is 33600000, while the sum is 59.

The spelling of 861785555540 in words is "eight hundred sixty-one billion, seven hundred eighty-five million, five hundred fifty-five thousand, five hundred forty".