216507 has 4 divisors (see below), whose sum is σ = 288680. Its totient is φ = 144336.

The previous prime is 216493. The next prime is 216509. The reversal of 216507 is 705612.

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

It is not a de Polignac number, because 216507 - 2⁷ = 216379 is a prime.

It is a D-number.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216509) 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, 36082 + ... + 36087.

It is an arithmetic number, because the mean of its divisors is an integer number (72170).

2²¹⁶⁵⁰⁷ is an apocalyptic number.

216507 is a deficient number, since it is larger than the sum of its proper divisors (72173).

216507 is an equidigital number, since it uses as much as digits as its factorization.

216507 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72172.

The product of its (nonzero) digits is 420, while the sum is 21.

The square root of 216507 is about 465.3031270043. The cubic root of 216507 is about 60.0469077626.

The spelling of 216507 in words is "two hundred sixteen thousand, five hundred seven".