216723499 has 4 divisors (see below), whose sum is σ = 222009480. Its totient is φ = 211437520.

The previous prime is 216723487. The next prime is 216723509. The reversal of 216723499 is 994327612.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216723499 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216723469) 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, 2642929 + ... + 2643010.

It is an arithmetic number, because the mean of its divisors is an integer number (55502370).

Almost surely, 2^216723499 is an apocalyptic number.

216723499 is a deficient number, since it is larger than the sum of its proper divisors (5285981).

216723499 is an equidigital number, since it uses as much as digits as its factorization.

216723499 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5285980.

The product of its digits is 163296, while the sum is 43.

The square root of 216723499 is about 14721.5318156773. The cubic root of 216723499 is about 600.6691599124.

The spelling of 216723499 in words is "two hundred sixteen million, seven hundred twenty-three thousand, four hundred ninety-nine".