55645591 has 2 divisors, whose sum is σ = 55645592. Its totient is φ = 55645590.

The previous prime is 55645571. The next prime is 55645621. The reversal of 55645591 is 19554655.

55645591 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 55645591 - 2²³ = 47256983 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55645501) 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, 27822795 + 27822796.

It is an arithmetic number, because the mean of its divisors is an integer number (27822796).

Almost surely, 2^55645591 is an apocalyptic number.

55645591 is a deficient number, since it is larger than the sum of its proper divisors (1).

55645591 is an equidigital number, since it uses as much as digits as its factorization.

55645591 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 135000, while the sum is 40.

The square root of 55645591 is about 7459.5972411384. The cubic root of 55645591 is about 381.7774326419. Note that the first 3 decimals are identical.

The spelling of 55645591 in words is "fifty-five million, six hundred forty-five thousand, five hundred ninety-one".