216392716921 has 8 divisors (see below), whose sum is σ = 216681089184. Its totient is φ = 216104528640.

The previous prime is 216392716909. The next prime is 216392716957. The reversal of 216392716921 is 129617293612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 216392716921 - 2⁹ = 216392716409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216392716961) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2393266 + ... + 2482036.

It is an arithmetic number, because the mean of its divisors is an integer number (27085136148).

Almost surely, 2^216392716921 is an apocalyptic number.

It is an amenable number.

216392716921 is a deficient number, since it is larger than the sum of its proper divisors (288372263).

216392716921 is a wasteful number, since it uses less digits than its factorization.

216392716921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91991.

The product of its digits is 489888, while the sum is 49.

The spelling of 216392716921 in words is "two hundred sixteen billion, three hundred ninety-two million, seven hundred sixteen thousand, nine hundred twenty-one".