216393929 has 2 divisors, whose sum is σ = 216393930. Its totient is φ = 216393928.

The previous prime is 216393923. The next prime is 216393937. The reversal of 216393929 is 929393612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 132250000 + 84143929 = 11500^2 + 9173^2 .

It is a cyclic number.

It is not a de Polignac number, because 216393929 - 2²⁰ = 215345353 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 216393929.

It is not a weakly prime, because it can be changed into another prime (216393923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108196964 + 108196965.

It is an arithmetic number, because the mean of its divisors is an integer number (108196965).

Almost surely, 2^216393929 is an apocalyptic number.

It is an amenable number.

216393929 is a deficient number, since it is larger than the sum of its proper divisors (1).

216393929 is an equidigital number, since it uses as much as digits as its factorization.

216393929 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 157464, while the sum is 44.

The square root of 216393929 is about 14710.3340886603. The cubic root of 216393929 is about 600.3645275620.

The spelling of 216393929 in words is "two hundred sixteen million, three hundred ninety-three thousand, nine hundred twenty-nine".