866542 has 4 divisors (see below), whose sum is σ = 1299816. Its totient is φ = 433270.

The previous prime is 866519. The next prime is 866573. The reversal of 866542 is 245668.

It is a semiprime because it is the product of two primes.

It is a nialpdrome in base 10.

It is a congruent number.

It is an unprimeable number.

866542 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 as a sum of consecutive naturals, namely, 216634 + ... + 216637.

It is an arithmetic number, because the mean of its divisors is an integer number (324954).

2⁸⁶⁶⁵⁴² is an apocalyptic number.

866542 is a deficient number, since it is larger than the sum of its proper divisors (433274).

866542 is a wasteful number, since it uses less digits than its factorization.

866542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433273.

The product of its digits is 11520, while the sum is 31.

The square root of 866542 is about 930.8823771025. The cubic root of 866542 is about 95.3373784559.

The spelling of 866542 in words is "eight hundred sixty-six thousand, five hundred forty-two".