55667561 has 2 divisors, whose sum is σ = 55667562. Its totient is φ = 55667560.

The previous prime is 55667531. The next prime is 55667581. The reversal of 55667561 is 16576655.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 55591936 + 75625 = 7456^2 + 275^2 .

It is a cyclic number.

It is not a de Polignac number, because 55667561 - 2¹⁸ = 55405417 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (55667531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27833780 + 27833781.

It is an arithmetic number, because the mean of its divisors is an integer number (27833781).

Almost surely, 2^55667561 is an apocalyptic number.

It is an amenable number.

55667561 is a deficient number, since it is larger than the sum of its proper divisors (1).

55667561 is an equidigital number, since it uses as much as digits as its factorization.

55667561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 189000, while the sum is 41.

The square root of 55667561 is about 7461.0696954257. The cubic root of 55667561 is about 381.8276705039.

The spelling of 55667561 in words is "fifty-five million, six hundred sixty-seven thousand, five hundred sixty-one".