861566388088 has 48 divisors (see below), whose sum is σ = 1879374350880. Its totient is φ = 369204901632.

The previous prime is 861566388077. The next prime is 861566388091. The reversal of 861566388088 is 880883665168.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3899920 + ... + 4114912.

It is an arithmetic number, because the mean of its divisors is an integer number (39153632310).

Almost surely, 2^861566388088 is an apocalyptic number.

It is an amenable number.

861566388088 is an abundant number, since it is smaller than the sum of its proper divisors (1017807962792).

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

861566388088 is a wasteful number, since it uses less digits than its factorization.

861566388088 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 225236 (or 225225 counting only the distinct ones).

The product of its (nonzero) digits is 106168320, while the sum is 67.

The spelling of 861566388088 in words is "eight hundred sixty-one billion, five hundred sixty-six million, three hundred eighty-eight thousand, eighty-eight".