864642 has 16 divisors (see below), whose sum is σ = 1762560. Its totient is φ = 282672.

The previous prime is 864641. The next prime is 864673. The reversal of 864642 is 246468.

It is not an unprimeable number, because it can be changed into a prime (864641) by changing a digit.

It is an upside-down number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1042 + ... + 1677.

It is an arithmetic number, because the mean of its divisors is an integer number (110160).

2⁸⁶⁴⁶⁴² is an apocalyptic number.

864642 is an abundant number, since it is smaller than the sum of its proper divisors (897918).

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

864642 is a wasteful number, since it uses less digits than its factorization.

864642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2777.

The product of its digits is 9216, while the sum is 30.

The square root of 864642 is about 929.8612799768. The cubic root of 864642 is about 95.2676478209.

The spelling of 864642 in words is "eight hundred sixty-four thousand, six hundred forty-two".