866642 has 16 divisors (see below), whose sum is σ = 1502592. Its totient is φ = 367200.

The previous prime is 866641. The next prime is 866653. The reversal of 866642 is 246668.

It is a happy number.

866642 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a nialpdrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 866599 and 866608.

It is not an unprimeable number, because it can be changed into a prime (866641) 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, 1142 + ... + 1742.

It is an arithmetic number, because the mean of its divisors is an integer number (93912).

2⁸⁶⁶⁶⁴² is an apocalyptic number.

866642 is a deficient number, since it is larger than the sum of its proper divisors (635950).

866642 is a wasteful number, since it uses less digits than its factorization.

866642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 713.

The product of its digits is 13824, while the sum is 32.

The square root of 866642 is about 930.9360880318. The cubic root of 866642 is about 95.3410456647.

The spelling of 866642 in words is "eight hundred sixty-six thousand, six hundred forty-two".