216851953 has 2 divisors, whose sum is σ = 216851954. Its totient is φ = 216851952.

The previous prime is 216851923. The next prime is 216852043. The reversal of 216851953 is 359158612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 207561649 + 9290304 = 14407^2 + 3048^2 .

It is a cyclic number.

It is not a de Polignac number, because 216851953 - 2¹³ = 216843761 is a prime.

It is not a weakly prime, because it can be changed into another prime (216851923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108425976 + 108425977.

It is an arithmetic number, because the mean of its divisors is an integer number (108425977).

Almost surely, 2^216851953 is an apocalyptic number.

It is an amenable number.

216851953 is a deficient number, since it is larger than the sum of its proper divisors (1).

216851953 is an equidigital number, since it uses as much as digits as its factorization.

216851953 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 64800, while the sum is 40.

The square root of 216851953 is about 14725.8939626768. The cubic root of 216851953 is about 600.7878105086.

The spelling of 216851953 in words is "two hundred sixteen million, eight hundred fifty-one thousand, nine hundred fifty-three".