216739 has 4 divisors (see below), whose sum is σ = 218056. Its totient is φ = 215424.

The previous prime is 216731. The next prime is 216743. The reversal of 216739 is 937612.

216739 is nontrivially palindromic in base 15.

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

It is a cyclic number.

It is not a de Polignac number, because 216739 - 2³ = 216731 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216731) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 369 + ... + 754.

It is an arithmetic number, because the mean of its divisors is an integer number (54514).

2²¹⁶⁷³⁹ is an apocalyptic number.

216739 is a deficient number, since it is larger than the sum of its proper divisors (1317).

216739 is a wasteful number, since it uses less digits than its factorization.

216739 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1316.

The product of its digits is 2268, while the sum is 28.

The square root of 216739 is about 465.5523601057. The cubic root of 216739 is about 60.0683480388.

The spelling of 216739 in words is "two hundred sixteen thousand, seven hundred thirty-nine".