216932621 has 2 divisors, whose sum is σ = 216932622. Its totient is φ = 216932620.

The previous prime is 216932609. The next prime is 216932623. The reversal of 216932621 is 126239612.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 191822500 + 25110121 = 13850^2 + 5011^2 .

It is a cyclic number.

It is not a de Polignac number, because 216932621 - 2¹⁸ = 216670477 is a prime.

Together with 216932623, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216932623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108466310 + 108466311.

It is an arithmetic number, because the mean of its divisors is an integer number (108466311).

Almost surely, 2^216932621 is an apocalyptic number.

It is an amenable number.

216932621 is a deficient number, since it is larger than the sum of its proper divisors (1).

216932621 is an equidigital number, since it uses as much as digits as its factorization.

216932621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7776, while the sum is 32.

The square root of 216932621 is about 14728.6326928198. The cubic root of 216932621 is about 600.8622981059.

The spelling of 216932621 in words is "two hundred sixteen million, nine hundred thirty-two thousand, six hundred twenty-one".