216732091 has 2 divisors, whose sum is σ = 216732092. Its totient is φ = 216732090.

The previous prime is 216732071. The next prime is 216732097. The reversal of 216732091 is 190237612.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216732091 is a prime.

It is not a weakly prime, because it can be changed into another prime (216732097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108366045 + 108366046.

It is an arithmetic number, because the mean of its divisors is an integer number (108366046).

Almost surely, 2^216732091 is an apocalyptic number.

216732091 is a deficient number, since it is larger than the sum of its proper divisors (1).

216732091 is an equidigital number, since it uses as much as digits as its factorization.

216732091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4536, while the sum is 31.

The square root of 216732091 is about 14721.8236302436. The cubic root of 216732091 is about 600.6770976476.

The spelling of 216732091 in words is "two hundred sixteen million, seven hundred thirty-two thousand, ninety-one".