55616161 has 2 divisors, whose sum is σ = 55616162. Its totient is φ = 55616160.

The previous prime is 55616159. The next prime is 55616191. The reversal of 55616161 is 16161655.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50140561 + 5475600 = 7081^2 + 2340^2 .

It is a cyclic number.

It is not a de Polignac number, because 55616161 - 2¹ = 55616159 is a prime.

Together with 55616159, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (55616101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27808080 + 27808081.

It is an arithmetic number, because the mean of its divisors is an integer number (27808081).

Almost surely, 2^55616161 is an apocalyptic number.

It is an amenable number.

55616161 is a deficient number, since it is larger than the sum of its proper divisors (1).

55616161 is an equidigital number, since it uses as much as digits as its factorization.

55616161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5400, while the sum is 31.

The square root of 55616161 is about 7457.6243536397. The cubic root of 55616161 is about 381.7101155912.

The spelling of 55616161 in words is "fifty-five million, six hundred sixteen thousand, one hundred sixty-one".