865138771200 has 648 divisors, whose sum is σ = 3151110475744. Its totient is φ = 208875110400.

The previous prime is 865138771193. The next prime is 865138771249. The reversal of 865138771200 is 2177831568.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 865138771200.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 713221794 + ... + 713223006.

Almost surely, 2^865138771200 is an apocalyptic number.

865138771200 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 865138771200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1575555237872).

865138771200 is an abundant number, since it is smaller than the sum of its proper divisors (2285971704544).

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

865138771200 is a wasteful number, since it uses less digits than its factorization.

865138771200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1571 (or 1541 counting only the distinct ones).

The product of its (nonzero) digits is 564480, while the sum is 48.

The spelling of 865138771200 in words is "eight hundred sixty-five billion, one hundred thirty-eight million, seven hundred seventy-one thousand, two hundred".