55151561 has 2 divisors, whose sum is σ = 55151562. Its totient is φ = 55151560.

The previous prime is 55151557. The next prime is 55151563. The reversal of 55151561 is 16515155.

It is a happy number.

55151561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 54479161 + 672400 = 7381^2 + 820^2 .

It is a cyclic number.

It is not a de Polignac number, because 55151561 - 2² = 55151557 is a prime.

Together with 55151563, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (55151563) 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, 27575780 + 27575781.

It is an arithmetic number, because the mean of its divisors is an integer number (27575781).

Almost surely, 2^55151561 is an apocalyptic number.

It is an amenable number.

55151561 is a deficient number, since it is larger than the sum of its proper divisors (1).

55151561 is an equidigital number, since it uses as much as digits as its factorization.

55151561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3750, while the sum is 29.

The square root of 55151561 is about 7426.4096978284. The cubic root of 55151561 is about 380.6442464718.

The spelling of 55151561 in words is "fifty-five million, one hundred fifty-one thousand, five hundred sixty-one".