861616 has 40 divisors (see below), whose sum is σ = 1959200. Its totient is φ = 366912.

The previous prime is 861613. The next prime is 861617. The reversal of 861616 is 616168.

861616 is nontrivially palindromic in base 13.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is not an unprimeable number, because it can be changed into a prime (861613) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5410 + ... + 5566.

It is an arithmetic number, because the mean of its divisors is an integer number (48980).

2⁸⁶¹⁶¹⁶ 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 861616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (979600).

861616 is an abundant number, since it is smaller than the sum of its proper divisors (1097584).

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

861616 is a wasteful number, since it uses less digits than its factorization.

861616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 186 (or 166 counting only the distinct ones).

The product of its digits is 1728, while the sum is 28.

The square root of 861616 is about 928.2327294380. The cubic root of 861616 is about 95.1563814020.

The spelling of 861616 in words is "eight hundred sixty-one thousand, six hundred sixteen".