216503971 has 2 divisors, whose sum is σ = 216503972. Its totient is φ = 216503970.

The previous prime is 216503953. The next prime is 216504019. The reversal of 216503971 is 179305612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 216503971 - 2⁵ = 216503939 is a prime.

It is not a weakly prime, because it can be changed into another prime (216503941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108251985 + 108251986.

It is an arithmetic number, because the mean of its divisors is an integer number (108251986).

Almost surely, 2^216503971 is an apocalyptic number.

216503971 is a deficient number, since it is larger than the sum of its proper divisors (1).

216503971 is an equidigital number, since it uses as much as digits as its factorization.

216503971 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11340, while the sum is 34.

The square root of 216503971 is about 14714.0739090165. The cubic root of 216503971 is about 600.4662773633.

The spelling of 216503971 in words is "two hundred sixteen million, five hundred three thousand, nine hundred seventy-one".