861966 has 24 divisors (see below), whose sum is σ = 2134704. Its totient is φ = 246240.

The previous prime is 861947. The next prime is 861977. The reversal of 861966 is 669168.

861966 = T₂₃₄ + T₂₃₅ + ... + T₂₆₁.

861966 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 861966.

It is a congruent number.

It is an unprimeable number.

861966 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3295 + ... + 3546.

It is an arithmetic number, because the mean of its divisors is an integer number (88946).

2⁸⁶¹⁹⁶⁶ is an apocalyptic number.

861966 is an abundant number, since it is smaller than the sum of its proper divisors (1272738).

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

861966 is a wasteful number, since it uses less digits than its factorization.

861966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6856 (or 6853 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 861966 is about 928.4212406015. The cubic root of 861966 is about 95.1692642582.

The spelling of 861966 in words is "eight hundred sixty-one thousand, nine hundred sixty-six".