216741649 has 2 divisors, whose sum is σ = 216741650. Its totient is φ = 216741648.

The previous prime is 216741593. The next prime is 216741659. The reversal of 216741649 is 946147612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 116100625 + 100641024 = 10775^2 + 10032^2 .

It is a cyclic number.

It is not a de Polignac number, because 216741649 - 2²⁵ = 183187217 is a prime.

It is a super-2 number, since 2×216741649² = 93953884822478402, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (216741659) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108370824 + 108370825.

It is an arithmetic number, because the mean of its divisors is an integer number (108370825).

Almost surely, 2^216741649 is an apocalyptic number.

It is an amenable number.

216741649 is a deficient number, since it is larger than the sum of its proper divisors (1).

216741649 is an equidigital number, since it uses as much as digits as its factorization.

216741649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 72576, while the sum is 40.

The square root of 216741649 is about 14722.1482467743. The cubic root of 216741649 is about 600.6859275771.

The spelling of 216741649 in words is "two hundred sixteen million, seven hundred forty-one thousand, six hundred forty-nine".