865813139100 has 1080 divisors, whose sum is σ = 3630080243328. Its totient is φ = 176751590400.

The previous prime is 865813139099. The next prime is 865813139111. The reversal of 865813139100 is 1931318568.

It is a happy number.

865813139100 is a `hidden beast` number, since 8 + 6 + 581 + 31 + 39 + 1 + 0 + 0 = 666.

865813139100 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 359 ways as a sum of consecutive naturals, for example, 159947994 + ... + 159953406.

Almost surely, 2^865813139100 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 865813139100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1815040121664).

865813139100 is an abundant number, since it is smaller than the sum of its proper divisors (2764267104228).

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

865813139100 is a wasteful number, since it uses less digits than its factorization.

865813139100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5497 (or 5474 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 45.

The spelling of 865813139100 in words is "eight hundred sixty-five billion, eight hundred thirteen million, one hundred thirty-nine thousand, one hundred".