55156561 has 2 divisors, whose sum is σ = 55156562. Its totient is φ = 55156560.

The previous prime is 55156531. The next prime is 55156583. The reversal of 55156561 is 16565155.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 40564161 + 14592400 = 6369^2 + 3820^2 .

It is a cyclic number.

It is not a de Polignac number, because 55156561 - 2¹⁹ = 54632273 is a prime.

It is not a weakly prime, because it can be changed into another prime (55156501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27578280 + 27578281.

It is an arithmetic number, because the mean of its divisors is an integer number (27578281).

Almost surely, 2^55156561 is an apocalyptic number.

It is an amenable number.

55156561 is a deficient number, since it is larger than the sum of its proper divisors (1).

55156561 is an equidigital number, since it uses as much as digits as its factorization.

55156561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 22500, while the sum is 34.

The square root of 55156561 is about 7426.7463266224. The cubic root of 55156561 is about 380.6557491001.

The spelling of 55156561 in words is "fifty-five million, one hundred fifty-six thousand, five hundred sixty-one".