861200816 has 80 divisors (see below), whose sum is σ = 1976659200. Its totient is φ = 355839744.

The previous prime is 861200803. The next prime is 861200827. The reversal of 861200816 is 618002168.

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, 348995 + ... + 351453.

It is an arithmetic number, because the mean of its divisors is an integer number (24708240).

Almost surely, 2^861200816 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 861200816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (988329600).

861200816 is an abundant number, since it is smaller than the sum of its proper divisors (1115458384).

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

861200816 is a wasteful number, since it uses less digits than its factorization.

861200816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2586 (or 2580 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 861200816 is about 29346.2231982243. The cubic root of 861200816 is about 951.4109471805.

The spelling of 861200816 in words is "eight hundred sixty-one million, two hundred thousand, eight hundred sixteen".