216504971 has 4 divisors (see below), whose sum is σ = 216874392. Its totient is φ = 216135552.

The previous prime is 216504941. The next prime is 216504973. The reversal of 216504971 is 179405612.

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 216504971 - 2⁶ = 216504907 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216504973) 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, 183830 + ... + 185003.

It is an arithmetic number, because the mean of its divisors is an integer number (54218598).

Almost surely, 2^216504971 is an apocalyptic number.

216504971 is a deficient number, since it is larger than the sum of its proper divisors (369421).

216504971 is an equidigital number, since it uses as much as digits as its factorization.

216504971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 369420.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 216504971 is about 14714.1078900489. The cubic root of 216504971 is about 600.4672018504.

The spelling of 216504971 in words is "two hundred sixteen million, five hundred four thousand, nine hundred seventy-one".