216124561 has 2 divisors, whose sum is σ = 216124562. Its totient is φ = 216124560.

The previous prime is 216124549. The next prime is 216124607. The reversal of 216124561 is 165421612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 184416400 + 31708161 = 13580^2 + 5631^2 .

It is a cyclic number.

It is not a de Polignac number, because 216124561 - 2⁹ = 216124049 is a prime.

It is not a weakly prime, because it can be changed into another prime (216124061) 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, 108062280 + 108062281.

It is an arithmetic number, because the mean of its divisors is an integer number (108062281).

Almost surely, 2^216124561 is an apocalyptic number.

It is an amenable number.

216124561 is a deficient number, since it is larger than the sum of its proper divisors (1).

216124561 is an equidigital number, since it uses as much as digits as its factorization.

216124561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2880, while the sum is 28.

The square root of 216124561 is about 14701.1754972179. The cubic root of 216124561 is about 600.1153120964.

The spelling of 216124561 in words is "two hundred sixteen million, one hundred twenty-four thousand, five hundred sixty-one".