861381786 has 16 divisors (see below), whose sum is σ = 1797666624. Its totient is φ = 274643424.

The previous prime is 861381757. The next prime is 861381791. The reversal of 861381786 is 687183168.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3120811 + ... + 3121086.

It is an arithmetic number, because the mean of its divisors is an integer number (112354164).

Almost surely, 2^861381786 is an apocalyptic number.

861381786 is an abundant number, since it is smaller than the sum of its proper divisors (936284838).

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

861381786 is a wasteful number, since it uses less digits than its factorization.

861381786 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6241925.

The product of its digits is 387072, while the sum is 48.

The square root of 861381786 is about 29349.3063972558. The cubic root of 861381786 is about 951.4775846697.

The spelling of 861381786 in words is "eight hundred sixty-one million, three hundred eighty-one thousand, seven hundred eighty-six".