216328332921 has 4 divisors (see below), whose sum is σ = 288437777232. Its totient is φ = 144218888612.

The previous prime is 216328332917. The next prime is 216328332989. The reversal of 216328332921 is 129233823612.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 216328332921 - 2² = 216328332917 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (216328330921) 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, 36054722151 + ... + 36054722156.

It is an arithmetic number, because the mean of its divisors is an integer number (72109444308).

Almost surely, 2^216328332921 is an apocalyptic number.

It is an amenable number.

216328332921 is a deficient number, since it is larger than the sum of its proper divisors (72109444311).

216328332921 is an equidigital number, since it uses as much as digits as its factorization.

216328332921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72109444310.

The product of its digits is 186624, while the sum is 42.

The spelling of 216328332921 in words is "two hundred sixteen billion, three hundred twenty-eight million, three hundred thirty-two thousand, nine hundred twenty-one".